diff --git a/cobc/ChangeLog b/cobc/ChangeLog
index 01cd211af..df2d87184 100644
--- a/cobc/ChangeLog
+++ b/cobc/ChangeLog
@@ -1,4 +1,22 @@
 
+2026-08-26  Nicolas Berthier <nicolas.berthier@ocamlpro.com>
+
+	* tree.c (warn_if_no_definition_seen_for_prototype): move to typeck.c,
+	  renamed into find_prototype_definition
+	* tree.c (cb_build_prototype): move check for missing definitions to the
+	  (unique) call-site in typeck.c
+	* typeck.c (setup_prototype, check_prototype_against_definition):
+	  report REPOSITORY entries that mismatch their definition
+	* typeck.c (try_get_program): handle USAGE OBJECT REFERENCE
+	* typeck.c (cb_check_conformance, cb_validate_oo_class_or_interface):
+	  add support for checking method invocations, both via INVOKE or inline;
+	  fix determination of last given argument
+	* parser.y (call_body): remove unneeded guard for call to
+	  cb_check_conformance (now dealt with internally in try_get_program)
+	* parser.y (clean_up_program): proper module type in signature
+	* tree.c, tree.h (cb_build_field_reference): add const attributes to arguments
+	* tree.c, tree.h (cb_build_object_reference): new function
+
 2026-08-26 Fabrice Le Fessant <fabrice.le_fessant@ocamlpro.com>
 
 	* ppparse.y (ppp_replace_list_add): fix bug #1071
@@ -19,6 +37,17 @@
 	* field.c (warn_pic_for_numeric_value_implied): Added fix to print
 	  Implied PIC warning only when needed
 
+2026-06-30  Saurabh Kumar <developer.saurabh@outlook.com>
+
+	* parser.y, reserved.c, scanner.l: add support for parsing INTERFACE-ID,
+	  METHOD-ID, FACTORY, OBJECT paragraphs, INVOKE statement and inline method
+	  invocation expression. Support CLASS and INTERFACE specifiers in REPOSITORY
+	  paragraph. Also support keywords SELF and ACTIVE-CLASS.
+	* tree.h, tree.c, typeck.c: add syntax validation logic to check OO inheritance
+	  list for duplicates, consistency with names specified in the REPOSITORY
+	  paragraph
+	* cobc.h: add new special contexts for OO constructs
+
 2026-06-11  Saurabh Kumar <developer.saurabh@outlook.com>
 
 	* parser.y, reserved.c: add support for parsing class attributes - AS literal,
diff --git a/cobc/cobc.h b/cobc/cobc.h
index 73a3a005f..9573b1a51 100644
--- a/cobc/cobc.h
+++ b/cobc/cobc.h
@@ -177,6 +177,10 @@ enum cb_current_date {
 #define	CB_CS_REPOSITORY		(COB_U64_C(1) << 42)
 #define	CB_CS_CALL_USING		(COB_U64_C(1) << 43)	/* within USING phrase of CALL statement */
 #define	CB_CS_READY_OR_RESET		(COB_U64_C(1) << 44)
+#define	CB_CS_CLASS_SPECIFIER		(COB_U64_C(1) << 45)
+#define	CB_CS_INTERFACE_SPECIFIER	(COB_U64_C(1) << 46)
+#define	CB_CS_FACTORY_PARAGRAPH		(COB_U64_C(1) << 47)
+#define	CB_CS_OBJECT_PARAGRAPH		(COB_U64_C(1) << 48)
 
 /* Support for cobc from stdin */
 #define COB_DASH			"-"
diff --git a/cobc/codegen.c b/cobc/codegen.c
index 96224c017..c631d68c7 100644
--- a/cobc/codegen.c
+++ b/cobc/codegen.c
@@ -14052,14 +14052,14 @@ codegen_internal (struct cb_program *prog, const int subsequent_call)
 		for (l = prog->entry_list; l; l = CB_CHAIN (l)) {
 			output_function_entry_function (prog, l, 1);
 		}
-	} else {
+	} else if (prog->prog_type == COB_MODULE_TYPE_PROGRAM) {
 		output_line ("/* PROGRAM-ID '%s' */", prog->orig_program_id);
 		output_newline ();
 		for (l = prog->entry_list; l; l = CB_CHAIN (l)) {
 			output_entry_function (prog, l, prog->parameter_list, 1);
 			progid++;
 		}
-	}
+	} /* TODO (OO): Handle other prog types. */
 
 	output_internal_function (prog, prog->parameter_list);
 
diff --git a/cobc/parser.y b/cobc/parser.y
index 806d2a443..57877618e 100644
--- a/cobc/parser.y
+++ b/cobc/parser.y
@@ -1471,7 +1471,7 @@ setup_program (cb_tree id, cb_tree as_literal, const enum cob_module_type type,
 
 	/* build encoded external PROGRAM-ID */
 	current_program->program_id
-		= cb_build_program_id (external_name, type == COB_MODULE_TYPE_FUNCTION);
+		= cb_build_program_id (external_name, type != COB_MODULE_TYPE_PROGRAM);
 
 	if (type == COB_MODULE_TYPE_PROGRAM) {
 		if (!main_flag_set
@@ -1529,12 +1529,18 @@ decrement_depth (const char *name, const unsigned char type)
 		} else if (type == COB_MODULE_TYPE_CLASS) {
 			cb_error (_("END CLASS '%s' is different from CLASS-ID '%s'"),
 				  name, stack_progid[depth]);
+		} else if (type == COB_MODULE_TYPE_INTERFACE) {
+			cb_error (_("END INTERFACE '%s' is different from INTERFACE-ID '%s'"),
+				  name, stack_progid[depth]);
+		} else if (type == COB_MODULE_TYPE_METHOD) {
+			cb_error (_("END METHOD '%s' is different from METHOD-ID '%s'"),
+				  name, stack_progid[depth]);
 		}
 	}
 }
 
 static void
-clean_up_program (cb_tree name, const unsigned char type)
+clean_up_program (cb_tree name, const enum cob_module_type type)
 {
 	char		*s;
 
@@ -1547,6 +1553,10 @@ clean_up_program (cb_tree name, const unsigned char type)
 			s = (char *)(CB_NAME (name));
 		}
 
+		/* CHECKME: shouldn' depth decrement also be perfomed when name
+		   is not given?  Maybe that's ok as per grammar rules that
+		   force END-X to be followed by a name for every OO
+		   construct... */
 		decrement_depth (s, type);
 	}
 
@@ -1660,7 +1670,7 @@ check_prototype_redefines_current_element (const cb_tree prototype_name)
 /* Returns 1 if the prototype has been duplicated. */
 static int
 check_for_duplicate_prototype (const cb_tree prototype_name,
-			       const cb_tree prototype)
+			       const struct cb_prototype *prototype)
 {
 	cb_tree	dup;
 
@@ -1673,9 +1683,8 @@ check_for_duplicate_prototype (const cb_tree prototype_name,
 		}
 
 		/* Check the duplicate prototypes match */
-		if (strcmp (CB_PROTOTYPE (prototype)->ext_name,
-			    CB_PROTOTYPE (dup)->ext_name)
-		    || CB_PROTOTYPE (prototype)->type != CB_PROTOTYPE (dup)->type) {
+		if (strcmp (prototype->ext_name, CB_PROTOTYPE (dup)->ext_name)
+		 || prototype->type != CB_PROTOTYPE (dup)->type) {
 			cb_error_x (prototype_name,
 				    _("duplicate REPOSITORY entries for '%s' do not match"),
 				    get_literal_or_word_name (prototype_name));
@@ -1690,11 +1699,59 @@ check_for_duplicate_prototype (const cb_tree prototype_name,
 	return 0;
 }
 
+/* Note: neither proto nor program may be NULL */
+static void
+check_prototype_against_definition (const struct cb_prototype *proto,
+				    const struct cb_program *program)
+{
+	if (program->prog_type == proto->type) {
+		return;
+	}
+	cb_error_x (CB_TREE (proto),
+		    _("%s REPOSITORY entry for '%s' does not match its definition"),
+		    cb_get_cob_module_type_string (proto->type),
+		    proto->ext_name);
+	cb_note_x (COB_WARNOPT_NONE, CB_TREE (program),
+		   _("'%s' defined as a %s here"),
+		   program->program_name,
+		   cb_get_cob_module_type_string (program->prog_type));
+}
+
+static struct cb_program *
+find_prototype_definition (const struct cb_prototype *proto)
+{
+	struct cb_program	*program = NULL;
+
+	program = cb_find_defined_program_by_id (proto->ext_name);
+
+	if (!program &&
+	    get_warn_opt_value (cb_warn_ignored_initial_val) != COBC_WARN_DISABLED) {
+		if (strcmp (proto->name, proto->ext_name) == 0) {
+			/*
+			  Warn if no definition seen for element with prototype-
+			  name.
+			*/
+			cb_warning_x (cb_warn_prototypes, CB_TREE (proto),
+				      _("no definition/prototype seen for %s '%s'"),
+				      cb_get_cob_module_type_string (proto->type), proto->name);
+		} else {
+			/*
+			  Warn if no definition seen for element with given
+			  external-name.
+			*/
+			cb_warning_x (cb_warn_prototypes, CB_TREE (proto),
+				      _("no definition/prototype seen for %s with external name '%s'"),
+				      cb_get_cob_module_type_string (proto->type), proto->ext_name);
+		}
+	}
+	return program;
+}
+
 static void
 setup_prototype (cb_tree prototype_name, cb_tree ext_name,
 		  const enum cob_module_type type, const int is_current_element)
 {
-	cb_tree	prototype;
+	struct cb_prototype *prototype;
 	int	name_redefinition_allowed;
 
 	if (!is_current_element
@@ -1702,28 +1759,47 @@ setup_prototype (cb_tree prototype_name, cb_tree ext_name,
 		return;
 	}
 
-	prototype = cb_build_prototype (prototype_name, ext_name, type);
+	prototype = CB_PROTOTYPE (cb_build_prototype (prototype_name, ext_name, type));
 
-	if (!is_current_element
-	 && check_for_duplicate_prototype (prototype_name, prototype)) {
-		return;
+	if (!is_current_element) {
+		const struct cb_program *program = find_prototype_definition (prototype);
+		if (check_for_duplicate_prototype (prototype_name, prototype)) {
+			return;
+		}
+		if (program) {
+			check_prototype_against_definition (prototype, program);
+		}
 	}
 
 	name_redefinition_allowed = type == COB_MODULE_TYPE_PROGRAM
 		&& is_current_element && cb_program_name_redefinition;
 	if (!name_redefinition_allowed) {
+		cb_tree p = CB_TREE (prototype);
 		if (CB_LITERAL_P (prototype_name)) {
-			cb_define (cb_build_reference ((const char *)CB_LITERAL (prototype_name)->data), prototype);
+			cb_define (cb_build_reference ((const char *)CB_LITERAL (prototype_name)->data), p);
 		} else {
-			cb_define (prototype_name, prototype);
+			cb_define (prototype_name, p);
 		}
 
-		if (type == COB_MODULE_TYPE_PROGRAM) {
+		switch (type) {
+		case COB_MODULE_TYPE_PROGRAM:
 			current_program->program_spec_list =
-				cb_list_add (current_program->program_spec_list, prototype);
-		} else { /* COB_MODULE_TYPE_FUNCTION */
+				cb_list_add (current_program->program_spec_list, p);
+			break;
+		case COB_MODULE_TYPE_FUNCTION:
 			current_program->user_spec_list =
-				cb_list_add (current_program->user_spec_list, prototype);
+				cb_list_add (current_program->user_spec_list, p);
+			break;
+		case COB_MODULE_TYPE_CLASS:
+			current_program->class_spec_list =
+				cb_list_add (current_program->class_spec_list, p);
+			break;
+		case COB_MODULE_TYPE_INTERFACE:
+			current_program->interface_spec_list =
+				cb_list_add (current_program->interface_spec_list, p);
+			break;
+		case COB_MODULE_TYPE_METHOD: /* unreachable... (for now) */
+			break;
 		}
 	}
 }
@@ -2561,10 +2637,10 @@ set_record_size (cb_tree min, cb_tree max)
 	}
 }
 
-/* Object-oriented class */
+/* Object-orientation helpers */
 
 static COB_INLINE void
-set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
+set_oo_class_attr (enum cb_oo_class_attribute attr, const char* attr_name)
 {
 	if (current_program->oo_class_attributes & attr) {							
 		emit_duplicate_clause_message (attr_name);						
@@ -2572,6 +2648,54 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 	current_program->oo_class_attributes |= attr;
 }
 
+/* Returns the program that corresponds to the currently defined class.
+
+   Returns NULL outside of a method definition. */
+static struct cb_program *
+current_self_class (void) {
+	struct cb_program *oo_class = current_program;
+	if (current_program->prog_type != COB_MODULE_TYPE_METHOD) {
+		cb_error (_("use of SELF outside of METHOD definition"));
+		return NULL;
+	}
+	while (oo_class && oo_class->prog_type == COB_MODULE_TYPE_METHOD) {
+		oo_class = oo_class->next_program;
+	}
+	return oo_class;
+}
+
+/* Returns the program that corresponds to the super class of the currently
+   defined class, if it is unique and defined.  Returns NULL in every other
+   case.
+
+   Returns NULL outside of a method implementation. */
+static struct cb_program *
+current_super_class (void) {
+	cb_tree super;
+	if (current_program->prog_type != COB_MODULE_TYPE_METHOD) {
+		cb_error (_("use of SUPER outside of METHOD definition"));
+		return NULL;
+	}
+	super = current_self_class ()->oo_inheritance_list;
+	if (unlikely (cb_list_length (super) == 0)) {
+		/* no declared inheritance (implcity Base)... */
+	} else if (cb_list_length (super) == 1) {
+		super = cb_ref (CB_VALUE (super));
+		if (CB_PROGRAM_P (super)) {
+			return CB_PROGRAM (super);
+		} else {
+			/* otherwise, it's only a prototype and we cannot check
+			   much more at the moment... or do we?  */
+		}
+	} else {
+		/* multiple inheritance case */
+		cb_warning (COBC_WARN_FILLER,
+			    _("use of SUPER in CLASS or INTERFACE with "
+			      "multiple inheritance may be ambiguous"));
+	}
+	return NULL;
+}
+
 %}
 
 %token TOKEN_EOF 0 "end of file"
@@ -2703,7 +2827,7 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token CLASS
 %token CLASS_ID		"CLASS-ID"
 %token CLASSIFICATION
-%token CLASS_NAME		"class-name"
+%token CLASS_NAME
 %token CLEAR_SELECTION		"CLEAR-SELECTION"
 %token CLINE
 %token CLINES			/* remark: not used here */
@@ -2838,20 +2962,24 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token END_ACCEPT		"END-ACCEPT"
 %token END_ADD  		"END-ADD"
 %token END_CALL 		"END-CALL"
+%token END_CLASS		"END CLASS"
 %token END_COMPUTE		"END-COMPUTE"
 %token END_COLOR		"END-COLOR"
 %token END_DELETE		"END-DELETE"
 %token END_DISPLAY		"END-DISPLAY"
 %token END_DIVIDE		"END-DIVIDE"
 %token END_EVALUATE		"END-EVALUATE"
+%token END_FACTORY		"END-FACTORY"
 %token END_FUNCTION		"END FUNCTION"
 %token END_IF			"END-IF"
+%token END_INTERFACE		"END INTERFACE"
 %token END_JSON			"END-JSON"
+%token END_METHOD		"END METHOD"
 %token END_MODIFY		"END-MODIFY"
 %token END_MULTIPLY		"END-MULTIPLY"
+%token END_OBJECT		"END-OBJECT"
 %token END_PERFORM		"END-PERFORM"
 %token END_PROGRAM		"END PROGRAM"
-%token END_CLASS		"END CLASS"
 %token END_READ			"END-READ"
 %token END_RECEIVE		"END-RECEIVE"
 %token END_RETURN		"END-RETURN"
@@ -2895,6 +3023,7 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token EXCLUSIVE
 %token EXHIBIT
 %token EXIT
+%token EXPANDS
 %token EXPONENTIATION		"exponentiation operator"
 %token EXTEND
 %token EXTENDED_SEARCH		"EXTENDED-SEARCH"
@@ -2954,6 +3083,7 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token FUNCTION_NAME		"intrinsic function name"
 %token FUNCTION_POINTER		"FUNCTION-POINTER"
 %token GENERATE
+%token GET
 %token GIVING
 %token GLOBAL
 %token GO
@@ -2990,6 +3120,7 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token IF
 %token IGNORE
 %token IGNORING
+%token IMPLEMENTS
 %token IN
 %token INDEPENDENT
 %token INDEX
@@ -3006,12 +3137,15 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token INSERT_ROWS		"INSERT-ROWS"
 %token INSPECT
 %token INSTALLATION		/* remark: not used here */
+%token INTERFACE
+%token INTERFACE_ID		"INTERFACE-ID"
 %token INTERMEDIATE
 %token INTERNAL
 %token INTO
 %token INTRINSIC
 %token INVALID			/* remark: not used here */
 %token INVALID_KEY		"INVALID KEY"
+%token INVOKE
 %token IS
 %token ITEM
 %token ITEM_TEXT		"ITEM-TEXT"
@@ -3089,6 +3223,8 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token MENU
 %token MERGE
 %token MESSAGE
+%token METHOD
+%token METHOD_ID
 %token MICROSECOND_TIME	"MICROSECOND-TIME"
 %token MINUS
 %token MIN_VAL			"MIN-VAL"
@@ -3172,6 +3308,8 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token ONLY
 %token ON_ESCAPE		"ON ESCAPE"
 %token ON_EXCEPTION		"ON EXCEPTION"
+%token OO_CLASS_NAME		"class-name"
+%token OO_INTERFACE_NAME	"interface-name"
 %token OPEN
 %token OPTIONAL
 %token OPTIONS
@@ -3184,6 +3322,7 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token OVERLAP_LEFT		"OVERLAP-LEFT"
 %token OVERLAP_TOP		"OVERLAP-TOP"
 %token OVERLINE
+%token OVERRIDE
 %token PACKED_DECIMAL		"PACKED-DECIMAL"
 %token PADDING
 %token PASCAL
@@ -3339,6 +3478,7 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token SELECTION_INDEX	"SELECTION-INDEX"
 %token SELECTION_TEXT	"SELECTION-TEXT"
 %token SELECT_ALL		"SELECTION-ALL"
+%token SELF
 %token SELF_ACT			"SELF-ACT"
 %token SEMI_COLON		"semi-colon"
 %token SEND
@@ -3401,6 +3541,7 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token SUBTRACT
 %token SUBWINDOW
 %token SUM
+%token SUPER
 %token SUPPRESS
 %token SUPPRESS_XML		"SUPPRESS"
 %token SYMBOL
@@ -3438,6 +3579,7 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %token TOK_AMPER		"&"
 %token TOK_CLOSE_PAREN		")"
 %token TOK_COLON		":"
+%token TOK_COLON_COLON          "::"
 %token TOK_DIV			"/"
 %token TOK_DOT			"."
 %token TOK_EQUAL		"="
@@ -3593,6 +3735,7 @@ set_oo_class_attr(enum cb_oo_class_attribute attr, const char* attr_name)
 %nonassoc INITIATE
 %nonassoc INQUIRE
 %nonassoc INSPECT
+%nonassoc INVOKE
 %nonassoc JSON
 %nonassoc MERGE
 %nonassoc MODIFY
@@ -3747,6 +3890,7 @@ source_element:
   program_definition
 | class_definition
 | function_definition
+| interface_definition
 | program_prototype
 | function_prototype
 ;
@@ -3777,8 +3921,120 @@ program_definition:
 class_definition:
   _identification_header
   class_id_paragraph
-  /* TODO: _program_body */
+  _class_body
+  {
+	cb_validate_program_data (current_program);
+  }
   end_class
+  {
+	cb_check_definition_matches_prototype (current_program);
+  }
+;
+
+_class_body:
+  _options_paragraph
+  _environment_division
+  {
+	cb_validate_program_environment (current_program);
+  }
+  _factory_or_instance_definition
+;
+
+interface_definition:
+  _identification_header
+  interface_id_paragraph
+  _interface_body
+  end_interface
+  {
+	cb_check_definition_matches_prototype (current_program);
+  }
+;
+
+_interface_body:
+  _options_paragraph
+  _environment_division
+  {
+	cb_validate_program_environment (current_program);
+	cb_validate_program_data (current_program);
+  }
+  _procedure_division
+;
+
+_factory_or_instance_definition:
+  /* empty */
+| factory_definition
+| instance_definition
+| factory_definition
+  instance_definition
+;
+
+factory_definition:
+  _identification_header
+  FACTORY
+  {
+	__CS_ENTER (CB_CS_FACTORY_PARAGRAPH);
+  }
+  _dot
+  _implements_clause
+  {
+	__CS_LEAVE (CB_CS_FACTORY_PARAGRAPH);
+  }
+  _oo_body
+  {
+	/* TODO: use a flag to denote that those are factory method definitions,
+	   or post-process the list of methods.  The flag approach may be
+	   necessary in case some checks performed during parsing depend on this
+	   context.  We could also generate distinct programs for factory and
+	   for instance.. */
+  }
+  END_FACTORY
+  _dot
+;
+
+instance_definition:
+  _identification_header
+  OBJECT
+  {
+	__CS_ENTER (CB_CS_OBJECT_PARAGRAPH);
+  }
+  _dot
+  _implements_clause
+  {
+	__CS_LEAVE (CB_CS_OBJECT_PARAGRAPH);
+  }
+  _oo_body
+  END_OBJECT
+  _dot
+;
+
+_oo_body:
+  _options_paragraph
+  _environment_division
+  {
+	cb_validate_program_environment (current_program);
+  }
+  _data_division
+  {
+	cb_validate_program_data (current_program);
+  }
+  _oo_procedure_division
+  {
+	/* Manual reset as a full OO construct like METHOD-ID can appear inside
+	   PROCEDURE DIVISIONs. */
+	cobc_in_procedure = 0;
+  }
+;
+
+method_definition:
+  _identification_header
+  method_id_header TOK_DOT method_signature _override _is_final _dot
+  {
+	/* The PROCEDURE DIVISION is optional in methods definitions, so we'll
+	   assume it is there already. */
+	header_check |= COBC_HD_PROCEDURE_DIVISION;
+  }
+  _program_body
+  end_method
 ;
 
 function_definition:
@@ -3821,11 +4077,36 @@ end_class:
 	last_source_line = cb_source_line;
 	check_area_a_of ("END CLASS");
   }
-  end_class_name _dot
+  OO_CLASS_NAME _dot
   {
+	cobc_in_id = 0;
 	clean_up_program ($3, COB_MODULE_TYPE_CLASS);
   }
+;
 
+end_interface:
+  END_INTERFACE
+  {
+	last_source_line = cb_source_line;
+	check_area_a_of ("END INTERFACE");
+  }
+  interface_id_name _dot
+  {
+	cobc_in_id = 0;
+	clean_up_program ($3, COB_MODULE_TYPE_INTERFACE);
+  }
+;
+
+end_method:
+  END_METHOD
+  {
+	last_source_line = cb_source_line;
+	check_area_a_of ("END METHOD");
+  }
+  _method_id_name _dot
+  {
+	clean_up_program ($3, COB_MODULE_TYPE_METHOD);
+  }
 ;
 
 end_function:
@@ -4007,29 +4288,49 @@ _default_display_clause:
 class_id_header:
   CLASS_ID
   {
-	cobc_in_id = 1;
+	__CS_CLEAR_ALL();
+	CB_UNSUPPORTED ("object-oriented COBOL");
+  }
+;
+
+interface_id_header:
+  INTERFACE_ID
+  {
+	__CS_CLEAR_ALL();
+	CB_UNSUPPORTED ("object-oriented COBOL (INTERFACE)");
   }
 ;
 
-class_id_name:
-  CLASS_NAME	{ $$ = $1; }
+_method_id_name:
+  /* empty */
+| method_id_name
+;
+
+method_id_name:
+  WORD
 | LITERAL
   {
 	cb_trim_program_id ($1);
   }
 ;
 
-parent_class_name: 
-  WORD
+interface_id_name:
+  WORD	{ $$ = $1; }
+| LITERAL
   {
-  	current_program->class_inheritance_list = 
-		cb_list_add(current_program->class_inheritance_list, $1);
+	cb_trim_program_id ($1);
   }
 ;
 
-parent_class_name_list:
-  parent_class_name
-| parent_class_name_list parent_class_name
+word_list:
+  WORD
+  {
+	$$ = CB_LIST_INIT ($1);
+  }
+| word_list WORD
+  {
+	$$ = cb_list_add ($1, $2);
+  }
 ;
 
 /* Parameterized classes not supported for now. */
@@ -4040,7 +4341,10 @@ class_param_list:
 
 _inherits_phrase:
   /* empty */
-| INHERITS _from parent_class_name_list
+| INHERITS _from word_list
+  {
+	current_program->oo_inheritance_list = $3;
+  }
 ;
 
 _using_phrase:
@@ -4048,13 +4352,18 @@ _using_phrase:
 | USING class_param_list
 ;
 
+_implements_clause:
+  /* empty */
+| IMPLEMENTS WORD _dot
+;
+
 class_attribute:
-  _is STATIC		{ set_oo_class_attr(CB_OO_CLASS_ATTR_STATIC, "STATIC"); }
-| _is PARTIAL		{ set_oo_class_attr(CB_OO_CLASS_ATTR_PARTIAL, "PARTIAL"); }
-| _is FINAL			{ set_oo_class_attr(CB_OO_CLASS_ATTR_FINAL, "FINAL"); }
-| _is ABSTRACT		{ set_oo_class_attr(CB_OO_CLASS_ATTR_ABSTRACT, "ABSTRACT"); }
-| _is PUBLIC		{ set_oo_class_attr(CB_OO_CLASS_ATTR_PUBLIC, "PUBLIC"); }
-| _is INTERNAL		{ set_oo_class_attr(CB_OO_CLASS_ATTR_INTERNAL, "INTERNAL"); }
+  _is STATIC		{ set_oo_class_attr (CB_OO_CLASS_ATTR_STATIC, "STATIC"); }
+| _is PARTIAL		{ set_oo_class_attr (CB_OO_CLASS_ATTR_PARTIAL, "PARTIAL"); }
+| _is FINAL		{ set_oo_class_attr (CB_OO_CLASS_ATTR_FINAL, "FINAL"); }
+| _is ABSTRACT		{ set_oo_class_attr (CB_OO_CLASS_ATTR_ABSTRACT, "ABSTRACT"); }
+| _is PUBLIC		{ set_oo_class_attr (CB_OO_CLASS_ATTR_PUBLIC, "PUBLIC"); }
+| _is INTERNAL		{ set_oo_class_attr (CB_OO_CLASS_ATTR_INTERNAL, "INTERNAL"); }
 ;
 
 _class_attributes:
@@ -4073,21 +4382,16 @@ _class_attributes:
 */
 
 class_id_paragraph:
-  class_id_header TOK_DOT class_id_name _as_literal
+  class_id_header TOK_DOT OO_CLASS_NAME _as_literal
   {
-	if (setup_program ($3, $4, COB_MODULE_TYPE_CLASS, 1)) {
+	if (setup_program ($3, $4, COB_MODULE_TYPE_CLASS, 0)) {
 		YYABORT;
 	}
-
-	__CS_CLEAR_ALL();
-	cobc_in_id = 0;
-
-	CB_UNSUPPORTED ("object-oriented COBOL");
   }
   _inherits_phrase
   _class_attributes
   _using_phrase
-  TOK_DOT
+  _dot
   {
 	/* check consistency of current attribues */
 	if (current_program->oo_class_attributes & CB_OO_CLASS_ATTR_FINAL
@@ -4103,11 +4407,46 @@ class_id_paragraph:
   }
 ;
 
-end_class_name:
-  CLASS_NAME
-| LITERAL
+interface_id_paragraph:
+  interface_id_header TOK_DOT interface_id_name _as_literal
   {
-	cb_trim_program_id ($1);
+	if (setup_program ($3, $4, COB_MODULE_TYPE_INTERFACE, 0)) {
+		YYABORT;
+	}
+  }
+  _inherits_phrase
+  _using_phrase
+  _dot
+;
+
+method_id_header:
+  METHOD_ID
+  {
+	__CS_CLEAR_ALL();
+  }
+;
+
+get_or_set:
+  GET
+| SET
+;
+
+method_signature:
+  method_id_name _as_literal
+  {
+	if (setup_program ($1, $2, COB_MODULE_TYPE_METHOD, 0)) {
+		YYABORT;
+	}
+  }
+| get_or_set PROPERTY WORD
+  {
+	/*
+	  TODO (OO): Call setup_program() with appropriate fields here.  Also
+	  set the property accessor type.
+	*/
+	if (setup_program ($3, NULL, COB_MODULE_TYPE_METHOD, 0)) {
+		YYABORT;
+	}
   }
 ;
 
@@ -4122,12 +4461,18 @@ _program_body:
   }
   _data_division
   {
-	/* note:
-	   we also validate all references we found so far here */
+	/* note: we also validate all references we found so far here */
 	cb_validate_program_data (current_program);
 	within_typedef_definition = 0;
   }
   _procedure_division
+  {  
+    /*
+      Manual reset as a full OO construct like METHOD-ID can appear inside
+      PROCEDURE DIVISIONs.
+    */
+    cobc_in_procedure = 0;  
+  }
 ;
 
 /* IDENTIFICATION DIVISION */
@@ -4445,7 +4790,8 @@ configuration_header:
   {
 	check_headers_present (COBC_HD_ENVIRONMENT_DIVISION, 0, 0, 0);
 	header_check |= COBC_HD_CONFIGURATION_SECTION;
-	if (current_program->nested_level) {
+	if (current_program->nested_level
+	 && current_program->prog_type == COB_MODULE_TYPE_PROGRAM) {
 		cb_error (_("%s not allowed in nested programs"), "CONFIGURATION SECTION");
 	}
   }
@@ -4675,6 +5021,18 @@ repository_list:
 | repository_list repository_name
 ;
 
+_expands_clause:
+  /* empty */
+| EXPANDS WORD
+  {
+	/*
+	  TODO (OO): Check that WORD is a class when used with the CLASS
+	  specifier and interface when used with the INTERFACE specifier.
+	*/
+  }
+USING word_list
+;
+
 repository_name:
   FUNCTION ALL INTRINSIC
   {
@@ -4698,6 +5056,28 @@ repository_name:
   {
 	yyerrok;
   }
+| CLASS
+  {
+	__CS_ENTER (CB_CS_CLASS_SPECIFIER);
+  }
+  WORD _as_literal _expands_clause
+  {
+	if ($3 != cb_error_node) {
+		setup_prototype ($3, $4, COB_MODULE_TYPE_CLASS, 0);
+	}
+	__CS_LEAVE (CB_CS_CLASS_SPECIFIER);
+  }
+| INTERFACE
+  {
+	__CS_ENTER (CB_CS_INTERFACE_SPECIFIER);
+  }
+  WORD _as_literal _expands_clause
+  {
+	if ($3 != cb_error_node) {
+		setup_prototype ($3, $4, COB_MODULE_TYPE_INTERFACE, 0);
+	}
+	__CS_LEAVE (CB_CS_INTERFACE_SPECIFIER);
+  }
 ;
 
 repository_name_list:
@@ -8225,8 +8605,10 @@ type_to_clause:
 
 usage_clause:
   _usage_is usage
-| USAGE _is conflict_usage	/* auto-enters CB_CS_USAGE */
+| USAGE _is 	/* auto-enters CB_CS_USAGE */
+  OBJECT REFERENCE _object_reference_type
   {
+	check_and_set_usage (CB_USAGE_OBJECT);
 	__CS_LEAVE (CB_CS_USAGE);
   }
 | USAGE _is WORD	/* MF extension for referencing types, full support would need
@@ -8395,6 +8777,7 @@ usage:
 	check_and_set_usage (CB_USAGE_POINTER);
 	if ($2) {
 		CB_PENDING ("POINTER TO type-name");
+		current_field->reference = $2;
 	}
 	current_field->flag_is_pointer = 1;
   }
@@ -8402,6 +8785,7 @@ usage:
   {
 	check_and_set_usage (CB_USAGE_PROGRAM_POINTER);
 	CB_PENDING ("POINTER TO prototype");	/* and function pointers... */
+	current_field->reference = $2;
 	current_field->flag_is_pointer = 1;
   }
 | PROGRAM_POINTER _to_program_type
@@ -8409,6 +8793,7 @@ usage:
 	check_and_set_usage (CB_USAGE_PROGRAM_POINTER);
 	if ($2) {
 		CB_PENDING ("POINTER TO prototype");
+		current_field->reference = $2;
 	}
 	current_field->flag_is_pointer = 1;
   }
@@ -8584,30 +8969,21 @@ _to_type_name:
 | _to type_name { $$ = $2;   }
 ;
 
-/* tokens that explicit need USAGE _is (because of reduce/reduce conflicts) */
-conflict_usage:
-  OBJECT REFERENCE _object_reference_type
-  {
-	check_and_set_usage (CB_USAGE_OBJECT);
-	CB_PENDING ("OBJECTS");
-  }
-;
-
 _object_reference_type:
   /* empty */
-| WORD
-| _factory_of ACTIVE_CLASS
-| _factory_of CLASS_NAME _only
+| OO_INTERFACE_NAME               { current_field->reference = cb_ref ($1); }
+| _factory_of ACTIVE_CLASS        { current_field->reference = cb_int0; }
+| _factory_of OO_CLASS_NAME _only { current_field->reference = cb_ref ($2); }
 ;
 
 _factory_of:
-  /* empty */
-| FACTORY _of
+  /* empty */ { current_field->flag_factory_reference = 0; }
+| FACTORY _of { current_field->flag_factory_reference = 1; }
 ;
 
 _only:
-  /* empty */ { $$ = NULL; }
-| ONLY	 { $$ = cb_int0; }
+  /* empty */ { current_field->flag_reference_only = 0; }
+| ONLY        { current_field->flag_reference_only = 1; }
 ;
 
 double_usage:
@@ -9365,7 +9741,8 @@ _local_storage_section:
 	check_headers_present (COBC_HD_DATA_DIVISION, 0, 0, 0);
 	header_check |= COBC_HD_LOCAL_STORAGE_SECTION;
 	current_storage = CB_STORAGE_LOCAL;
-	if (current_program->nested_level) {
+	if (current_program->nested_level
+	 && current_program->prog_type == COB_MODULE_TYPE_PROGRAM) {
 		cb_error (_("%s not allowed in nested programs"), "LOCAL-STORAGE");
 	} else if (cb_local_implies_recursive) {
 		current_program->flag_recursive = 1;
@@ -11217,7 +11594,7 @@ _procedure_division:
 | procedure_division
 ;
 
-procedure_division:
+procedure_division_header:
   PROCEDURE
   {
 	check_area_a_of ("PROCEDURE DIVISION");
@@ -11228,6 +11605,7 @@ procedure_division:
 	cobc_in_procedure = 1U;
 	cb_set_system_names ();
 	last_source_line = cb_source_line;
+	header_check |= COBC_HD_PROCEDURE_DIVISION;
 
 	cb_prof_procedure_division (
 		current_program,
@@ -11236,14 +11614,17 @@ procedure_division:
 		);
   }
   DIVISION
+;
+
+procedure_division_sections:
   _mnemonic_conv _conv_linkage _procedure_using_chaining _procedure_returning
   {
-	cb_tree call_conv = $4;
-	if ($5) {
-		call_conv = $5;
-		if ($4) {
-			/* note: $3 is likely to be a reference to SPECIAL-NAMES */
-			cb_error_x ($5, _("%s and %s are mutually exclusive"),
+	cb_tree call_conv = $1;
+	if ($2) {
+		call_conv = $2;
+		if ($1) {
+			/* note: $2 is likely to be a reference to SPECIAL-NAMES */
+			cb_error_x ($2, _("%s and %s are mutually exclusive"),
 				"CALL-CONVENTION", "WITH LINKAGE");
 		}
 	}
@@ -11256,17 +11637,16 @@ procedure_division:
 	} else if (!current_program->entry_convention) {
 		current_program->entry_convention = cb_int (CB_CONV_COBOL);
 	}
-	header_check |= COBC_HD_PROCEDURE_DIVISION;
   }
   _dot_or_else_area_a
   _procedure_declaratives
   {
 	if (current_program->flag_main
-	 && !current_program->flag_chained && $6) {
+	 && !current_program->flag_chained && $3) {
 		cb_error (_("executable program requested but PROCEDURE/ENTRY has USING clause"));
 	}
 
-	emit_main_entry (current_program, $6);
+	emit_main_entry (current_program, $3);
 
 	cb_check_definition_matches_prototype (current_program);
   }
@@ -11287,6 +11667,18 @@ procedure_division:
 		emit_statement (cb_build_perform_exit (current_section));
 	}
   }
+;
+
+_oo_procedure_division:
+  /* empty */
+| procedure_division_header
+  _dot_or_else_area_a
+  method_list
+;
+
+procedure_division:
+  procedure_division_header
+  procedure_division_sections
 |
   {
 	cb_tree label;
@@ -11563,7 +11955,7 @@ _procedure_returning:
 		} else if (f->flag_occurs) {
 			cb_error (_("RETURNING item should not have OCCURS"));
 		} else {
-			if (current_program->prog_type == COB_MODULE_TYPE_FUNCTION) {
+			if (current_program->prog_type != COB_MODULE_TYPE_PROGRAM) {
 				if (f->flag_any_length) {
 					cb_error (_("function RETURNING item may not be ANY LENGTH"));
 				}
@@ -11572,9 +11964,9 @@ _procedure_returning:
 #if 0	/* doesn't work for programs, will be fixed with allocating in the source-unit */
 			current_program->returning = $2;
 #else
-			if (current_program->prog_type == COB_MODULE_TYPE_FUNCTION) {
+			if (current_program->prog_type != COB_MODULE_TYPE_PROGRAM) {
 				current_program->returning = $2;
-			} else {
+			} else if (current_program->prog_type == COB_MODULE_TYPE_PROGRAM) {
 				CB_PENDING ("program RETURNING");
 			}
 #endif
@@ -11662,6 +12054,12 @@ procedure:
   }
 ;
 
+/* Method list */
+
+method_list:
+  method_definition
+| method_list method_definition
+;
 
 /* Section/Paragraph */
 
@@ -11943,7 +12341,7 @@ statement:
 | initiate_statement
 | inquire_statement
 | inspect_statement
-/* | TODO: invoke_statement */
+| invoke_statement
 | json_generate_statement
 | json_parse_statement
 | merge_statement
@@ -12864,22 +13262,13 @@ call_body:
 	}
 
 	/* Check parameter conformance, if we can work out what is being called. */
-	if (CB_LITERAL_P ($4)) {
-		cb_check_conformance ($4, $8, $9);
-	} else if (CB_REFERENCE_P ($4)) {
-		cb_tree	ref = cb_ref ($4);
-		if ((CB_FIELD_P (ref) && CB_FIELD (ref)->flag_item_78)
-		 || CB_PROGRAM_P (ref)
-		 || CB_PROTOTYPE_P (ref)) {
-			cb_check_conformance ($4, $8, $9);
-		}
-	}
+	(void) cb_check_conformance ($4, NULL, $8, $9, 0);
 
 	/* For CALL ... RETURNING NOTHING, set the call convention bit */
 	if (call_nothing) {
 		call_conv |= CB_CONV_NO_RET_UPD;
 	}
-	cb_emit_call ($4, $8, $9, CB_PAIR_X ($10), CB_PAIR_Y ($10),
+	cb_emit_call ($4, NULL, $8, $9, CB_PAIR_X ($10), CB_PAIR_Y ($10),
 		      cb_int (call_conv), $2, $6);
 	emit_prof_call (COB_PROF_EXIT_CALL,
 			target_name[0] == 0 ? "(dynamic)" : target_name,
@@ -15271,6 +15660,24 @@ inspect_body:
   }
 ;
 
+/* INVOKE statement */
+
+invoke_statement:
+  INVOKE
+  id_or_class_name
+  id_or_lit
+  call_using
+  call_returning
+  {
+	(void) cb_check_conformance ($2, $3, $4, $5, 0);
+  }
+;
+
+id_or_class_name:
+  identifier
+| OO_CLASS_NAME
+;
+
 _backward:
   /* empty */	{ $$ = NULL; }
 | BACKWARD		{ $$ = cb_int0; }
@@ -19867,6 +20274,7 @@ identifier_or_file_name:
 		$$ = cb_error_node;
 	}
   }
+| oo_identifier
 ;
 
 /* guarantees a reference to a validated field-reference (or cb_error_node) */
@@ -19905,6 +20313,44 @@ identifier:
 		$$ = cb_error_node;
 	}
   }
+| oo_identifier
+;
+
+/* TODO: make the semantic actions below return field references, so this can
+   then be merged into identifier_1? */
+oo_identifier:
+  SELF
+  {
+	cb_tree x = cb_validate_oo_class_or_interface (current_self_class ());
+	if (x != cb_error_node) {
+		$$ = cb_build_object_reference (CB_PROGRAM (x), 0);
+	} else {
+		$$ = cb_error_node;
+	}
+  }
+| SUPER
+  {
+	/* Note: warns in case of multiple inheritance... may we return a list
+	   instead? */
+	cb_tree x = cb_validate_oo_class_or_interface (current_super_class ());
+	if (x != cb_error_node) {
+		$$ = cb_build_object_reference (CB_PROGRAM (x), 0);
+	} else {
+		$$ = cb_error_node;
+	}
+  }
+| OO_CLASS_NAME OF SUPER
+  {
+	cb_tree x = cb_ref ($1);
+	if (CB_PROGRAM_P (x)) {
+		/* TODO: check super is actually inherited by the current
+		   class... */
+		x = cb_validate_oo_class_or_interface (CB_PROGRAM (x));
+		$$ = cb_build_object_reference (CB_PROGRAM (x), 0);
+	} else {
+		$$ = cb_error_node;
+	}
+  }
 ;
 
 identifier_1:
@@ -20337,6 +20783,49 @@ function:
   {
 	$$ = cb_build_intrinsic ($1, $2, $3, 1);
   }
+| id_or_class_name TOK_COLON_COLON literal inline_invoke_args
+  {
+	$$ = cb_check_conformance ($1, $3, $4, NULL, 1);
+  }
+;
+
+inline_invoke_args:
+  /* empty */	%prec SHIFT_PREFER
+  {
+	$$ = NULL;
+  }
+| TOK_OPEN_PAREN inline_invoke_args_list TOK_CLOSE_PAREN
+  {
+	if (cb_list_length ($2) > MAX_CALL_FIELD_PARAMS) {
+		cb_error_x (CB_TREE (current_statement),
+			    _("number of arguments exceeds maximum %d"),
+			    MAX_CALL_FIELD_PARAMS);
+	}
+	$$ = $2;
+  }
+| TOK_OPEN_PAREN TOK_CLOSE_PAREN
+  {
+	$$ = NULL;
+  }
+;
+
+inline_invoke_args_list:
+  inline_invoke_arg
+| inline_invoke_args_list _e_sep inline_invoke_arg
+  {
+	$$ = cb_list_append ($1, $3);
+  }
+;
+
+inline_invoke_arg:
+  OMITTED
+  {
+	$$ = CB_BUILD_PAIR (cb_int (CB_CALL_BY_REFERENCE), cb_null);
+  }
+| exp %prec SHIFT_PREFER
+  {
+	$$ = cb_build_call_parameter ($1, CB_CALL_BY_REFERENCE, CB_SIZE_UNSET);
+  }
 ;
 
 func_no_parm:
@@ -20880,6 +21369,7 @@ _is_equal:		| IS | TOK_EQUAL;
 _is_are:	| IS | ARE ;
 _is_are_equal:		| IS | ARE | TOK_EQUAL;
 _is_in:		| IS | IN ;
+_is_final:		| _is FINAL ;
 _key:		| KEY ;
 _line:		| LINE ;
 _line_or_lines:	| LINE | LINES ;
@@ -20897,6 +21387,7 @@ _on_for:	| ON | FOR ;
 _onoff_status:	| STATUS IS | STATUS | IS ;
 _other:		| OTHER ;
 _others:		| OTHERS ;
+_override:		| OVERRIDE ;
 _procedure:	| PROCEDURE ;
 _program:	| PROGRAM ;
 _protected:	| PROTECTED ;
diff --git a/cobc/reserved.c b/cobc/reserved.c
index 4a92aecf0..ff8d5dfaf 100644
--- a/cobc/reserved.c
+++ b/cobc/reserved.c
@@ -1252,8 +1252,8 @@ static struct cobc_reserved default_reserved_words[] = {
   { "EXPAND",		0, 1, EXPAND,		/* ACU extension */
 				0, CB_CS_GRAPHICAL_CONTROL | CB_CS_INQUIRE_MODIFY
   },
-  { "EXPANDS",			0, 1, -1,			/* 2002 (C/S) */
-				0, 0
+  { "EXPANDS",			0, 1, EXPANDS,			/* 2002 (C/S) */
+				0, CB_CS_CLASS_SPECIFIER | CB_CS_INTERFACE_SPECIFIER
 	/* FIXME: 2014 Context-sensitive to class-specifier and
 	   interface-specifier of REPOSITORY paragraph */
   },
@@ -1442,8 +1442,8 @@ static struct cobc_reserved default_reserved_words[] = {
   { "GENERATE",			0, 0, GENERATE,			/* 2002 */
 				0, 0
   },
-  { "GET",			0, 0, -1,			/* 2002 */
-				0, 0
+  { "GET",			0, 0, GET,			/* 2002 */
+				0,
   },
   { "GIVING",			0, 0, GIVING,			/* 2002 */
 				0, 0
@@ -1562,8 +1562,8 @@ static struct cobc_reserved default_reserved_words[] = {
   { "IGNORING",			0, 1, IGNORING,			/* 2002 (C/S) */
 				0, CB_CS_READ
   },
-  { "IMPLEMENTS",		0, 1, -1,			/* 2002 (C/S) */
-				0, 0
+  { "IMPLEMENTS",		0, 1, IMPLEMENTS,			/* 2002 (C/S) */
+				0, CB_CS_FACTORY_PARAGRAPH | CB_CS_OBJECT_PARAGRAPH
 	/* FIXME: 2014 Context-sensitive to FACTORY and OBJECT paragraph */
   },
   { "IN",			0, 0, IN,			/* 2002 */
@@ -1617,10 +1617,10 @@ static struct cobc_reserved default_reserved_words[] = {
   { "INSTALLATION",			0, 1, INSTALLATION,			/* 85 (later: C/S) */
 				0, CB_CS_DAY /* HACK, we only want it to normally be not usable */
   },
-  { "INTERFACE",		0, 0, -1,			/* 2002 */
+  { "INTERFACE",		0, 0, INTERFACE,			/* 2002 */
 				0, 0
   },
-  { "INTERFACE-ID",		0, 0, -1,			/* 2002 */
+  { "INTERFACE-ID",		0, 0, INTERFACE_ID,			/* 2002 */
 				0, 0
   },
   { "INTERMEDIATE",		0, 1, INTERMEDIATE,		/* 2014 (C/S) */
@@ -1638,7 +1638,7 @@ static struct cobc_reserved default_reserved_words[] = {
   { "INVALID",			0, 0, INVALID,			/* 2002 */
 				0, 0
   },
-  { "INVOKE",			0, 0, -1,			/* 2002 */
+  { "INVOKE",			0, 0, INVOKE,			/* 2002 */
 				0, 0
   },
   { "IS",			0, 0, IS,			/* 2002 */
@@ -1870,10 +1870,10 @@ static struct cobc_reserved default_reserved_words[] = {
   { "MESSAGE-TAG",			0, 0, -1,			/* COBOL 2023 MCS */
 				0, 0
   },
-  { "METHOD",			0, 0, -1,			/* 2002 */
+  { "METHOD",			0, 0, METHOD,			/* 2002 */
 				0, 0
   },
-  { "METHOD-ID",		0, 0, -1,			/* 2002 */
+  { "METHOD-ID",		0, 0, METHOD_ID,			/* 2002 */
 				0, 0
   },
   { "MICROSECOND-TIME",		0, 1, MICROSECOND_TIME,		/* ACU extension */
@@ -2605,7 +2605,7 @@ static struct cobc_reserved default_reserved_words[] = {
   { "SELECTION-TEXT",			0, 1, SELECTION_TEXT,			/* ACU extension */
 				0, CB_CS_GRAPHICAL_CONTROL | CB_CS_INQUIRE_MODIFY
   },
-  { "SELF",			0, 0, -1,			/* 2002 */
+  { "SELF",			0, 0, SELF,			/* 2002 */
 				0, 0
   },
   { "SELF-ACT",			0, 1, SELF_ACT,			/* ACU extension */
@@ -2799,7 +2799,7 @@ static struct cobc_reserved default_reserved_words[] = {
   { "SUM",			0, 0, SUM,			/* 2002 */
 				0, 0
   },
-  { "SUPER",			0, 0, -1,			/* 2002 */
+  { "SUPER",			0, 0, SUPER,			/* 2002 */
 				0, 0
   },
   { "SUPPRESS",			0, 0, SUPPRESS,			/* 2002 */
diff --git a/cobc/scanner.l b/cobc/scanner.l
index ae868118a..3ce2658ed 100644
--- a/cobc/scanner.l
+++ b/cobc/scanner.l
@@ -666,6 +666,26 @@ H#[0-9A-Za-z]+ {
 	RETURN_TOK (END_CLASS);
 }
 
+"END"[ ,;\n]+"FACTORY"/[ .,;\n] {
+	count_lines (yytext);
+	RETURN_TOK (END_FACTORY);
+}
+
+"END"[ ,;\n]+"OBJECT"/[ .,;\n] {
+	count_lines (yytext);
+	RETURN_TOK (END_OBJECT);
+}
+
+"END"[ ,;\n]+"METHOD"/[ .,;\n] {
+	count_lines (yytext);
+	RETURN_TOK (END_METHOD);
+}
+
+"END"[ ,;\n]+"INTERFACE"/[ .,;\n] {
+	count_lines (yytext);
+	RETURN_TOK (END_INTERFACE);
+}
+
 "PICTURE"[ ,;\n]+"SYMBOL"/[ .,;\n] {
 	if (lookup_reserved_word ("SYMBOL")) {
 		count_lines (yytext);
@@ -1064,10 +1084,10 @@ H#[0-9A-Za-z]+ {
 			yylval = cb_build_alphanumeric_literal (yytext, (size_t)yyleng);
 			RETURN_TOK (LITERAL);
 		}
-	} else if ((second_last_token == CLASS_ID && last_token == TOK_DOT) 
-		     || last_token == END_CLASS) {
+	} else if ((second_last_token == CLASS_ID && last_token == TOK_DOT)
+		    || last_token == END_CLASS) {
 		yylval = cb_build_reference (yytext);
-		RETURN_TOK (CLASS_NAME);
+		RETURN_TOK (OO_CLASS_NAME);
 	}
 
 	/* Check reserved word */
@@ -1105,6 +1125,20 @@ H#[0-9A-Za-z]+ {
 			RETURN_TOK (USER_FUNCTION_NAME);
 		}
 	}
+	for (l = current_program->class_spec_list; l; l = CB_CHAIN (l)) {
+		x = CB_VALUE (l);
+		if (!strcasecmp (yytext, CB_PROTOTYPE (x)->name)) {
+			yylval = cb_build_reference (yytext);
+			RETURN_TOK (OO_CLASS_NAME);
+		}
+	}
+	for (l = current_program->interface_spec_list; l; l = CB_CHAIN (l)) {
+		x = CB_VALUE (l);
+		if (!strcasecmp (yytext, CB_PROTOTYPE (x)->name)) {
+			yylval = cb_build_reference (yytext);
+			RETURN_TOK (OO_INTERFACE_NAME);
+		}
+	}
 	if (cobc_allow_program_name) {
 		for (l = current_program->program_spec_list; l; l = CB_CHAIN (l)) {
 			x = CB_VALUE (l);
@@ -1247,6 +1281,11 @@ H#[0-9A-Za-z]+ {
 	RETURN_TOK (TOK_COLON);
 }
 
+"::" {
+	yylval = NULL;
+	RETURN_TOK (TOK_COLON_COLON);
+}
+
 "=" {
 	yylval = NULL;
 	RETURN_TOK (TOK_EQUAL);
diff --git a/cobc/tree.c b/cobc/tree.c
index 75116f218..d639b3bef 100644
--- a/cobc/tree.c
+++ b/cobc/tree.c
@@ -1469,6 +1469,8 @@ cb_tree_category (cb_tree x)
 					x->category = CB_CATEGORY_DATA_POINTER;
 				} else if (f->usage == CB_USAGE_PROGRAM_POINTER) {
 					x->category = CB_CATEGORY_PROGRAM_POINTER;
+				} else if (f->usage == CB_USAGE_OBJECT) {
+					x->category = CB_CATEGORY_OBJECT_REFERENCE;
 				} else if (f->pic) {
 					x->category = f->pic->category;
 				/* FIXME: Hack for CGI to not abort */
@@ -5125,7 +5127,7 @@ cb_build_filler (void)
   If ref != NULL, other attributes are set to the same as ref.
 */
 cb_tree
-cb_build_field_reference (struct cb_field *f, cb_tree ref)
+cb_build_field_reference (const struct cb_field *f, const cb_tree ref)
 {
 	cb_tree		x;
 	struct cb_word	*word;
@@ -5141,6 +5143,27 @@ cb_build_field_reference (struct cb_field *f, cb_tree ref)
 	return x;
 }
 
+/*
+  Return a reference to the program p.
+  If ref != NULL, other attributes are set to the same as ref.
+*/
+cb_tree
+cb_build_object_reference (const struct cb_program *p, const cb_tree ref)
+{
+	cb_tree		x;
+	struct cb_word	*word;
+
+	x = cb_build_reference (p->program_name);
+	word = CB_REFERENCE (x)->word;
+	if (ref) {
+		memcpy (x, ref, sizeof (struct cb_reference));
+	}
+	x->category = CB_CATEGORY_OBJECT_REFERENCE;
+	CB_REFERENCE (x)->word = word;
+	CB_REFERENCE (x)->value = CB_TREE (p);
+	return x;
+}
+
 static void
 cb_define_system_name (const char *name)
 {
@@ -6932,44 +6955,6 @@ cb_build_xml_parse (cb_tree data, cb_tree proc,
 
 /* Prototypes */
 
-static void
-warn_if_no_definition_seen_for_prototype (const struct cb_prototype *proto)
-{
-	struct cb_program	*program;
-	const char		*error_msg;
-
-	program = cb_find_defined_program_by_id (proto->ext_name);
-	if (program) {
-		return;
-	}
-
-	if (get_warn_opt_value (cb_warn_ignored_initial_val) != COBC_WARN_DISABLED) {
-		if (strcmp (proto->name, proto->ext_name) == 0) {
-			/*
-			  Warn if no definition seen for element with prototype-
-			  name.
-			*/
-			if (proto->type == COB_MODULE_TYPE_FUNCTION) {
-				error_msg = _("no definition/prototype seen for FUNCTION '%s'");
-			} else { /* PROGRAM_TYPE */
-				error_msg = _("no definition/prototype seen for PROGRAM '%s'");
-			}
-			cb_warning_x (cb_warn_prototypes, CB_TREE (proto), error_msg, proto->name);
-		} else {
-			/*
-			  Warn if no definition seen for element with given
-			  external-name.
-			*/
-			if (proto->type == COB_MODULE_TYPE_FUNCTION) {
-				error_msg = _("no definition/prototype seen for FUNCTION with external name '%s'");
-			} else { /* PROGRAM_TYPE */
-				error_msg = _("no definition/prototype seen for PROGRAM with external name '%s'");
-			}
-			cb_warning_x (cb_warn_prototypes, CB_TREE (proto), error_msg, proto->ext_name);
-		}
-	}
-}
-
 cb_tree
 cb_build_prototype (const cb_tree prototype_name, const cb_tree ext_name,
 		    const enum cob_module_type type)
@@ -7001,8 +6986,6 @@ cb_build_prototype (const cb_tree prototype_name, const cb_tree ext_name,
 
 	prototype->type = type;
 
-	warn_if_no_definition_seen_for_prototype (prototype);
-
 	return CB_TREE (prototype);
 }
 
@@ -7670,6 +7653,35 @@ cb_build_prof_call (enum cb_prof_call prof_call,
 	return CB_BUILD_FUNCALL_3 (func_name, cb_int (prof_call), cb_int (func_arg1), cb_int (func_arg2));
 }
 
+/* Object-oriented */
+
+const char *
+cb_get_cob_module_type_string (enum cob_module_type prog_type)
+{
+	switch (prog_type) {
+	default:
+	case COB_MODULE_TYPE_PROGRAM: 		return "PROGRAM";
+	case COB_MODULE_TYPE_FUNCTION: 		return "FUNCTION";
+	case COB_MODULE_TYPE_CLASS: 		return "CLASS";
+	case COB_MODULE_TYPE_INTERFACE: 	return "INTERFACE";
+	case COB_MODULE_TYPE_METHOD: 		return "METHOD";
+	}
+}
+
+int
+cb_search_in_prototypes (cb_tree list, cb_tree name)
+{
+	cb_tree l;
+	
+	for (l = list; l; l = CB_CHAIN (l)) {
+		const char * const x_name = CB_PROTOTYPE (CB_VALUE (l))->name;
+		if (strcasecmp (x_name, CB_NAME (name)) == 0) {
+			return 0;
+		}
+	}
+	return 1;
+}
+
 /* Allocate a procedure description record and add it at the end of
  * the procedure_list of the current program. The index of the
  * procedure will be the position in the list. There is an invariant
diff --git a/cobc/tree.h b/cobc/tree.h
index 1e72b9b76..f8ad700bd 100644
--- a/cobc/tree.h
+++ b/cobc/tree.h
@@ -525,6 +525,13 @@ enum cb_oo_class_attribute {
 	CB_OO_CLASS_ATTR_INTERNAL		= 0x20
 };
 
+/* Object-orinted method property accessor type */
+enum cb_oo_property_accessor {
+	CB_OO_ACCESS_NONE	= 0,	/* Default, the method is neither a getter nor a setter */
+	CB_OO_ACCESS_GET	= 1,	/* Getter method */
+	CB_OO_ACCESS_SET	= 2		/* Setter method */
+};
+
 
 /* Reserved word list structure */
 struct cobc_reserved {
@@ -921,6 +928,7 @@ struct cb_field {
 	cb_tree			external_definition;	/* by SAME AS / LIKE data-name or
 											 by type-name (points to field) */
 	cb_tree			like_modifier;	/* set for LIKE, may contain a length modifier */
+	cb_tree			reference;
 
 	int			id;		/* Field id */
 	int			size;		/* Field size */
@@ -1018,6 +1026,8 @@ struct cb_field {
 	unsigned int flag_is_verified	: 1;	/* Has been verified */
 
 	unsigned int flag_had_definition_note : 1;	/* had its defintion output */
+	unsigned int flag_factory_reference : 1;	/* OBJECT REFERENCE FACTORY */
+	unsigned int flag_reference_only : 1;	/* OBJECT REFERENCE _ ONLY */
 };
 
 #define CB_FIELD(x)		(CB_TREE_CAST (CB_TAG_FIELD, struct cb_field, x))
@@ -1408,6 +1418,7 @@ struct cb_xml_parse {
 
 struct cb_call {
 	struct cb_tree_common	common;		/* Common values */
+	cb_tree			obj_or_class;		/* INVOKE class name or object reference */
 	cb_tree			name;		/* CALL name */
 	cb_tree			args;		/* Arguments */
 	cb_tree			stmt1;		/* ON EXCEPTION */
@@ -1832,6 +1843,9 @@ struct nested_list {
 	struct cb_program	*nested_prog;
 };
 
+/* CHECKME: a new struct cb_object_class (and cb_object_class_signature?) with
+   specific fields would be convenient when it comes to further
+   type-checking... */
 struct cb_program {
 	struct cb_tree_common	common;		/* Common values */
 
@@ -1869,13 +1883,13 @@ struct cb_program {
 	cb_tree			cb_sort_return;		/* SORT-RETURN */
 	cb_tree			cb_call_params;		/* Number of CALL params */
 	cb_tree			mnemonic_spec_list;	/* MNEMONIC spec */
-	cb_tree			class_spec_list;	/* CLASS spec */
-	cb_tree			interface_spec_list;	/* INTERFACE spec */
+	cb_tree			class_spec_list;	/* CLASS spec (prototypes only) */
+	cb_tree			interface_spec_list;	/* INTERFACE spec (prototypes only) */
 	cb_tree			function_spec_list;	/* FUNCTION spec */
 	cb_tree			user_spec_list;		/* User FUNCTION spec */
 	cb_tree			program_spec_list;	/* PROGRAM spec */
 	cb_tree			property_spec_list;	/* PROPERTY spec */
-	cb_tree			class_inheritance_list;	/* List of Inherited Classes (OOP) */
+	cb_tree			oo_inheritance_list;	/* List of Inherited Classes (OOP) */
 	struct cb_alter_id	*alter_gotos;		/* ALTER ids */
 	struct cb_field		*working_storage;	/* WORKING-STORAGE */
 	struct cb_field		*local_storage;		/* LOCAL-STORAGE */
@@ -1926,7 +1940,7 @@ struct cb_program {
 	cob_u8_t	high_value;			/* High-value for this program */
 	cob_u16_t	low_value_n;			/* National Low-value */
 	cob_u16_t	high_value_n;			/* National High-value  */
-	enum cob_module_type	prog_type;			/* Program type (program = 0, function = 1, OO class = 2) */
+	enum cob_module_type	prog_type;			/* Program type */
 	cob_u8_t 	oo_class_attributes;			/* OO class attributes */
 	cb_tree			entry_convention;	/* ENTRY convention / PROCEDURE convention */
 	struct literal_list	*decimal_constants;
@@ -1967,7 +1981,7 @@ struct cb_program {
 #define CB_PROGRAM(x)	(CB_TREE_CAST (CB_TAG_PROGRAM, struct cb_program, x))
 #define CB_PROGRAM_P(x)	(CB_TREE_TAG (x) == CB_TAG_PROGRAM)
 
-/* Function prototype */
+/* Prototype (function, class, or interface) */
 
 struct cb_prototype {
 	struct cb_tree_common	common;
@@ -2173,8 +2187,10 @@ extern void			cb_finalize_cd (struct cb_cd *,
 
 extern cb_tree			cb_build_filler (void);
 extern cb_tree			cb_build_reference (const char *);
-extern cb_tree			cb_build_field_reference (struct cb_field *,
-							  cb_tree);
+extern cb_tree			cb_build_field_reference (const struct cb_field *,
+							  const cb_tree);
+extern cb_tree			cb_build_object_reference (const struct cb_program *,
+							   const cb_tree);
 extern const char		*cb_define (cb_tree, cb_tree);
 extern char			*cb_to_cname (const char *);
 extern void			cb_set_system_names (void);
@@ -2415,6 +2431,9 @@ extern void		cb_validate_program_environment (struct cb_program *);
 extern void		cb_validate_program_data (struct cb_program *);
 extern void		cb_validate_program_body (struct cb_program *);
 
+extern void		cb_validate_oo_program_data (struct cb_program *);
+extern cb_tree		cb_validate_oo_class_or_interface (struct cb_program *);
+
 extern cb_tree		cb_build_expr (cb_tree);
 extern cb_tree		cb_build_cond (cb_tree);
 
@@ -2464,7 +2483,7 @@ extern void		cb_emit_allocate_characters (cb_tree, cb_tree, cb_tree);
 extern void		cb_emit_alter (cb_tree, cb_tree);
 extern void		cb_emit_free (cb_tree);
 
-extern void		cb_emit_call (cb_tree, cb_tree, cb_tree, cb_tree,
+extern void		cb_emit_call (cb_tree, cb_tree, cb_tree, cb_tree, cb_tree,
 				      cb_tree, cb_tree, cb_tree, cb_tree);
 
 extern void		cb_emit_cancel (cb_tree);
@@ -2601,7 +2620,8 @@ extern cb_tree		cb_build_write_advancing_lines (cb_tree, cb_tree);
 extern cb_tree		cb_build_write_advancing_mnemonic (cb_tree, cb_tree);
 extern cb_tree		cb_build_write_advancing_page (cb_tree);
 extern cb_tree		cb_check_sum_field (cb_tree x);
-extern void		cb_check_conformance (cb_tree, cb_tree, cb_tree);
+extern cb_tree		cb_check_conformance (cb_tree, cb_tree, cb_tree, cb_tree,
+					      int inline_invocation);
 extern void		cb_emit_initiate (cb_tree rep);
 extern void		cb_emit_terminate (cb_tree rep);
 extern void		cb_emit_generate (cb_tree rep);
@@ -2617,6 +2637,9 @@ extern cb_tree		cb_build_xml_parse (cb_tree, cb_tree,
 extern void		cb_emit_json_generate (cb_tree, cb_tree, cb_tree,
 					       cb_tree, cb_tree);
 
+extern const char	*cb_get_cob_module_type_string (enum cob_module_type);
+extern int		cb_search_in_prototypes (cb_tree prototypes, cb_tree name);
+
 #ifdef	COB_TREE_DEBUG
 extern cb_tree		cobc_tree_cast_check (const cb_tree, const char *,
 					      const int, const enum cb_tag);
diff --git a/cobc/typeck.c b/cobc/typeck.c
index f29df4c8d..df675130a 100644
--- a/cobc/typeck.c
+++ b/cobc/typeck.c
@@ -3064,6 +3064,21 @@ set_argument_defaults (cb_tree argument, cb_tree parameter, const struct cb_fiel
 
 }
 
+cb_tree
+cb_validate_oo_class_or_interface (struct cb_program *prog) {
+	if (!prog) {
+		return cb_error_node;
+	}
+	if (prog->prog_type != COB_MODULE_TYPE_CLASS
+	 && prog->prog_type != COB_MODULE_TYPE_INTERFACE) {
+		cb_error_x (CB_TREE (prog),
+			    _("CLASS or INTERFACE expected (got %s '%s')"),
+			    cb_get_cob_module_type_string (prog->prog_type),
+			    prog->program_name);
+		return cb_error_node;
+	}
+	return CB_TREE (prog);
+}
 
 void
 cb_validate_parameters_and_returning (struct cb_program *prog, cb_tree using_list)
@@ -3153,6 +3168,26 @@ cb_validate_parameters_and_returning (struct cb_program *prog, cb_tree using_lis
 	}
 }
 
+/* Returns NULL on figurative constants */
+static COB_INLINE const char *
+try_get_literal_data (cb_tree ref) {
+	if (CB_LITERAL_P (ref)) {
+		return (char *) CB_LITERAL (ref)->data;
+	} else if (CB_REFERENCE_P (ref)) {
+		ref = cb_ref (ref);
+		if (ref == cb_error_node) {
+			return NULL;
+		}
+		if (CB_FIELD_P (ref) && CB_FIELD (ref)->flag_item_78) {
+			cb_tree x = CB_VALUE (CB_FIELD (ref)->values);
+			if (!CB_LITERAL_P (x)) {
+				return NULL;
+			}
+			return (char *) CB_LITERAL (x)->data;
+		}
+	}
+	return NULL;
+}
 
 /* TODO: Add params differing in BY REFERENCE/VALUE and OPTIONAL to testsuite */
 
@@ -3163,26 +3198,25 @@ try_get_program (cb_tree prog_ref)
 	const char		*name_str;
 	cb_tree			ref;
 
-	if (CB_LITERAL_P (prog_ref)
+	name_str = try_get_literal_data (prog_ref);
+	if (name_str
 	    /* && TODO: Check user wants checks on this kind of CALL. */) {
-		name_str = (char *) CB_LITERAL (prog_ref)->data;
 		program = cb_find_defined_program_by_name (name_str);
 	} else if (CB_REFERENCE_P (prog_ref)) {
 		ref = cb_ref (prog_ref);
 		if (ref == cb_error_node) {
 			return NULL;
 		}
-
-		if (CB_FIELD_P (ref) && CB_FIELD (ref)->flag_item_78
-		    /* && TODO: Check user wants checks on this kind of CALL. */) {
-			cb_tree x = CB_VALUE (CB_FIELD (ref)->values);
-			if (!CB_LITERAL_P (x)) {
-				/* in theory this could be a figurative constant,
-				   in this case there is no matching program */
-				return NULL;
+		if (CB_FIELD_P (ref)
+		 && CB_FIELD (ref)->usage == CB_USAGE_OBJECT
+		 && CB_FIELD (ref)->reference) {
+			cb_tree x = CB_FIELD (ref)->reference;
+			if (CB_PROGRAM_P (x)) {
+				program = CB_PROGRAM (x);
+			} else if (CB_PROTOTYPE_P (x)) {
+				name_str = CB_PROTOTYPE (x)->ext_name;
+				program = cb_find_defined_program_by_id (name_str);
 			}
-			name_str = (char *) CB_LITERAL (x)->data;
-			program = cb_find_defined_program_by_name (name_str);
 		} else if (CB_PROTOTYPE_P (ref)) {
 			name_str = CB_PROTOTYPE (ref)->ext_name;
 			program = cb_find_defined_program_by_id (name_str);
@@ -3565,7 +3599,7 @@ check_argument_conformance (struct cb_program *program, cb_tree argument_tripple
 		return;
 	}
 
-	param_ref = cb_build_field_reference ((struct cb_field *)param_field, NULL);
+	param_ref = cb_build_field_reference (param_field, NULL);
 
 	/*
 	  Check the definition of the argument is compatible with the parameter.
@@ -3630,9 +3664,27 @@ check_argument_conformance (struct cb_program *program, cb_tree argument_tripple
 	}
 }
 
-void
-cb_check_conformance (cb_tree prog_ref, cb_tree using_list,
-		   cb_tree returning)
+static struct cb_program *
+try_get_method (struct cb_program *class, cb_tree oo_method_name) {
+	struct cb_program	*method = NULL;
+	const char * method_name = try_get_literal_data (oo_method_name);
+	if (method_name) {
+		struct nested_list* m;
+		for (m = class->nested_prog_list; m && !method; m = m->next) {
+			if (strcasecmp (method_name, m->nested_prog->program_name) == 0) {
+				method = m->nested_prog;
+			}
+		}
+	}
+	return method;
+}
+
+/* When inline_invocation is set, returns a reference to the field of the
+   *CALLED* program/function/method if it is found, or cb_error_node otheriwse.
+   This is used for type-checking inline method invocations. */
+cb_tree
+cb_check_conformance (cb_tree prog_ref, cb_tree oo_method_name, cb_tree using_list,
+		      cb_tree returning, int inline_invocation)
 {
 	struct cb_program	*program = NULL;
 	cb_tree			l;
@@ -3642,15 +3694,37 @@ cb_check_conformance (cb_tree prog_ref, cb_tree using_list,
 	const struct cb_field	*prog_returning_field;
 	const struct cb_field	*call_returning_field;
 
-	/* Try to get the program referred to by prog_ref. */
-	program = try_get_program (prog_ref);
+	if (oo_method_name) {
+		/* prog_ref may be either: (i) a user-defined class or interface
+		   name (listed in the REPOSITORY paragraph); (ii) an identifier
+		   (expected with usage OBJECT REFERENCE, maybe to a factory);
+		   (iii) SELF (cb_int0); or SUPER (cb_int1). */
+		struct cb_program	*oo_class = NULL;
+		int			factory_method_invocation = 0;
+		if (CB_PROGRAM_P (prog_ref)) {
+			oo_class = CB_PROGRAM (prog_ref);
+			factory_method_invocation = 1;
+		} else {
+			/* TODO: decompose that check to set
+			   factory_method_invocation when needed */
+			oo_class = try_get_program (prog_ref);
+		}
+		COB_UNUSED (factory_method_invocation); /* for now */
+		l = cb_validate_oo_class_or_interface (oo_class);
+		/* TODO: Walk up the class hierarchy/DAG, starting from
+		   oo_class, checking matching methods...  For now we only check
+		   a method in oo_class, if any. */
+		if (l != cb_error_node) {
+			program = try_get_method (CB_PROGRAM (l), oo_method_name);
+		}
+	} else {
+		program = try_get_program (prog_ref);
+	}
 	if (!program) {
-		/*
-		 */
 		for (l = using_list; l;	l = CB_CHAIN (l)) {
 			set_argument_defaults (l, NULL, NULL);
 		}
-		return;
+		return cb_error_node;
 	}
 
 	/*
@@ -3662,8 +3736,8 @@ cb_check_conformance (cb_tree prog_ref, cb_tree using_list,
 	     l && param_num <= program->num_proc_params;
 	     l = CB_CHAIN (l), ++param_num) {
 		check_argument_conformance (program, l, param_num);
-		last_arg = l;
 	}
+	last_arg = l;
 
 	/* If there are more params in the using list than in the prototype, error */
 	if (l && param_num > program->num_proc_params) {
@@ -3717,11 +3791,19 @@ cb_check_conformance (cb_tree prog_ref, cb_tree using_list,
 	} else if (returning && !program->returning) {
 		/* CHECKME: do we want to cater for RETURNING internally setting RETURN-CODE? */
 		cb_warning_x (cb_warn_repository_checks, returning,
-			_("unexpected RETURNING item"));
-	} else if (!returning && program->returning) {
-		cb_warning_x (cb_warn_repository_checks, returning,
-			_("expecting a RETURNING item, but none provided"));
+			      _("unexpected RETURNING item"));
+	} else if (inline_invocation && !program->returning) {
+		cb_warning (cb_warn_repository_checks,
+			    _("invalid inline invocation of a method with no RETURNING"));
+	} else if (!returning && !inline_invocation && program->returning) {
+		cb_warning (cb_warn_repository_checks,
+			    _("expecting a RETURNING item, but none provided"));
 	}
+
+	if (program->returning && inline_invocation) {
+		return program->returning;
+	}
+	return cb_error_node;
 }
 
 static int
@@ -4814,6 +4896,46 @@ validate_assign_name (cb_tree origin, struct cb_program * const prog)
 	}
 }
 
+void
+cb_validate_oo_program_data (struct cb_program *prog) {
+	cb_tree l, x, inheritable_prototypes = NULL;
+
+	if (prog->prog_type == COB_MODULE_TYPE_CLASS) {
+		inheritable_prototypes = prog->class_spec_list;
+	} else /* if (prog->prog_type == COB_MODULE_TYPE_INTERFACE) */ {
+		inheritable_prototypes = prog->interface_spec_list;
+	}
+	for (l = prog->oo_inheritance_list; l; l = CB_CHAIN (l)) {
+		const cb_tree y = CB_VALUE (l);
+		if (strcasecmp (prog->program_id, CB_NAME (y)) == 0) {
+			cb_error_x (l, _("cyclically inheriting %s '%s'"),
+				    cb_get_cob_module_type_string (prog->prog_type),
+				    CB_NAME (y));
+			cb_note_x (COB_WARNOPT_NONE, CB_TREE (prog), _("'%s' defined here"),
+				   CB_NAME (y));
+		}
+
+		/* Check for parent name in REPOSITORY paragraph */
+		if (cb_search_in_prototypes (inheritable_prototypes, y) == 1) {
+			cb_error_x (l, _("inherited %s '%s' not found in REPOSITORY paragraph"),
+				    cb_get_cob_module_type_string (prog->prog_type),
+				    CB_NAME (y));
+		}
+
+		/* Check for duplicate parent name */
+		for (x = CB_CHAIN (l); x; x = CB_CHAIN (x)) {
+			if (strcasecmp (CB_NAME (y), CB_NAME (CB_VALUE (x))) == 0) {
+				cb_error_x (x, _("duplicate parent %s '%s'"),
+					    cb_get_cob_module_type_string (prog->prog_type),
+					    CB_NAME (CB_VALUE (x)));
+				cb_note_x (COB_WARNOPT_NONE, l, _("'%s' defined here"),
+					   CB_NAME (y));
+				break;
+			}
+		}
+	}
+}
+
 void
 cb_validate_program_data (struct cb_program *prog)
 {
@@ -4911,6 +5033,11 @@ cb_validate_program_data (struct cb_program *prog)
 		         and free it here directly */
 	}
 
+	if (prog->prog_type == COB_MODULE_TYPE_CLASS
+	 || prog->prog_type == COB_MODULE_TYPE_INTERFACE) {
+		cb_validate_oo_program_data (prog);
+	}
+
 	/* Check ODO items */
 	for (l = cb_depend_check; l; l = CB_CHAIN (l)) {
 		struct cb_field		*depfld = NULL;
@@ -8799,7 +8926,7 @@ get_constant_call_name (cb_tree prog)
 }
 
 void
-cb_emit_call (cb_tree prog, cb_tree par_using, cb_tree returning,
+cb_emit_call (cb_tree prog, cb_tree oo_method, cb_tree par_using, cb_tree returning,
 	      cb_tree on_exception, cb_tree not_on_exception,
 	      cb_tree convention, cb_tree newthread, cb_tree handle)
 {
@@ -8820,6 +8947,8 @@ cb_emit_call (cb_tree prog, cb_tree par_using, cb_tree returning,
 	int				call_conv;
 	unsigned int		numargs;
 
+	COB_UNUSED (oo_method);
+
 	if (CB_INTRINSIC_P (prog)) {
 		if (CB_INTRINSIC (prog)->intr_tab->category != CB_CATEGORY_ALPHANUMERIC) {
 			cb_error_x (CB_TREE (current_statement),
diff --git a/libcob/ChangeLog b/libcob/ChangeLog
index 77bfbf84a..af9fc8ae8 100644
--- a/libcob/ChangeLog
+++ b/libcob/ChangeLog
@@ -6,6 +6,11 @@
 	  and fflush only is last operation was a write
 	* call.c (cob_get_buff): protect call to cob_free
 
+2026-06-30  Saurabh Kumar <developer.saurabh@outlook.com>
+
+	* common.h (cob_module_type): add COB_MODULE_TYPE_CLASS,
+	  COB_MODULE_TYPE_INTERFACE, COB_MODULE_TYPE_METHOD
+
 2026-03-02  Fabrice Le Fessant <fabrice.le_fessant@ocamlpro.com>
 
 	* coblocal.h, common.c, profiling.c: rename is_test to cob_is_test
diff --git a/libcob/common.h b/libcob/common.h
index b2b3167d2..9329daef6 100644
--- a/libcob/common.h
+++ b/libcob/common.h
@@ -1252,7 +1252,9 @@ typedef struct __cob_screen {
 enum cob_module_type {
 	COB_MODULE_TYPE_PROGRAM		= 0,
 	COB_MODULE_TYPE_FUNCTION	= 1,
-	COB_MODULE_TYPE_CLASS		= 2
+	COB_MODULE_TYPE_CLASS		= 2,
+	COB_MODULE_TYPE_INTERFACE	= 3,
+	COB_MODULE_TYPE_METHOD		= 4
 };
 
 /*
diff --git a/tests/testsuite.src/syn_definition.at b/tests/testsuite.src/syn_definition.at
index 17e49ee9f..a8ff76dcd 100644
--- a/tests/testsuite.src/syn_definition.at
+++ b/tests/testsuite.src/syn_definition.at
@@ -1276,7 +1276,7 @@ AT_DATA([prog.cob], [
 ])
 
 AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
-[prog.cob:3: error: syntax error, unexpected IDENTIFICATION, expecting CLASS-ID or FUNCTION-ID or PROGRAM-ID
+[prog.cob:3: error: syntax error, unexpected IDENTIFICATION, expecting CLASS-ID or FUNCTION-ID or INTERFACE-ID or PROGRAM-ID
 ])
 AT_CLEANUP
 
diff --git a/tests/testsuite.src/syn_misc.at b/tests/testsuite.src/syn_misc.at
index 8f239fefd..2de35319a 100644
--- a/tests/testsuite.src/syn_misc.at
+++ b/tests/testsuite.src/syn_misc.at
@@ -3987,12 +3987,12 @@ AT_DATA([prog.cob], [
 AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
 [prog.cob:12: error: syntax error, unexpected DELIMITED
 prog.cob:15: error: syntax error, unexpected END-STRING, expecting INTO
-prog.cob:17: error: syntax error, unexpected END-STRING, expecting Identifier
+prog.cob:17: error: syntax error, unexpected END-STRING, expecting class-name or SELF or SUPER or Identifier
 prog.cob:19: error: syntax error, unexpected DELIMITED
 prog.cob:24: error: syntax error, unexpected DELIMITED, expecting INTO
 prog.cob:32: error: syntax error, unexpected DELIMITED
 prog.cob:34: error: syntax error, unexpected Identifier, expecting INTO
-prog.cob:37: error: syntax error, unexpected END-UNSTRING, expecting Identifier
+prog.cob:37: error: syntax error, unexpected END-UNSTRING, expecting class-name or SELF or SUPER or Identifier
 prog.cob:38: error: syntax error, unexpected DELIMITED
 prog.cob:43: error: syntax error, unexpected DELIMITED, expecting INTO
 ])
@@ -4371,8 +4371,8 @@ prog.cob:22: error: 'f' is not a field
 prog.cob:22: error: 3 is not an alphanumeric literal
 prog.cob:22: error: 2 is not an alphanumeric literal
 prog.cob:22: error: invalid target for TRANSFORM
-prog.cob:23: error: syntax error, unexpected intrinsic function name, expecting Identifier
-prog.cob:24: error: syntax error, unexpected Literal, expecting Identifier
+prog.cob:23: error: syntax error, unexpected intrinsic function name, expecting class-name or SELF or SUPER or Identifier
+prog.cob:24: error: syntax error, unexpected Literal, expecting class-name or SELF or SUPER or Identifier
 prog.cob:25: error: invalid target for REPLACING
 ])
 AT_CLEANUP
@@ -6565,7 +6565,7 @@ prog.cob:49: error: JSON/XML GENERATE receiving item must be alphanumeric or nat
 prog.cob:51: error: JSON/XML GENERATE receiving item may not have JUSTIFIED clause
 prog.cob:53: error: JSON/XML GENERATE receiving item may not be subscripted
 prog.cob:54: error: JSON/XML GENERATE receiving item may not be reference modified
-prog.cob:57: error: syntax error, unexpected intrinsic function name, expecting Identifier
+prog.cob:57: error: syntax error, unexpected intrinsic function name, expecting class-name or SELF or SUPER or Identifier
 prog.cob:59: error: JSON/XML GENERATE input record may not be reference modified
 prog.cob:61: error: JSON/XML GENERATE input record may not have RENAMES clause
 prog.cob:66: error: JSON/XML GENERATE input record has subrecords with non-unique names
@@ -6603,7 +6603,7 @@ prog.cob:133: error: SUPPRESS item with WHEN clause must be elementary
 prog.cob:133: error: SUPPRESS item must be a child of the input record
 prog.cob:132: error: SUPPRESS item may not be an ignored item in JSON/XML GENERATE
 prog.cob:132: error: SUPPRESS item with WHEN clause must be elementary
-prog.cob:136: error: syntax error, unexpected intrinsic function name, expecting EVERY or WHEN or Identifier
+prog.cob:136: error: syntax error, unexpected intrinsic function name
 prog.cob:142: warning: OCCURS items in JSON/XML GENERATE is not implemented
 prog.cob:140: error: SUPPRESS item may not be subscripted
 prog.cob:139: error: SUPPRESS item may not be reference modified
diff --git a/tests/testsuite.src/syn_oo.at b/tests/testsuite.src/syn_oo.at
index e8f320c26..93f00a6c4 100644
--- a/tests/testsuite.src/syn_oo.at
+++ b/tests/testsuite.src/syn_oo.at
@@ -50,8 +50,8 @@ AT_DATA([prog1.cob], [
 ])
 
 AT_CHECK([$COMPILE_ONLY prog1.cob], [1], [],
-[prog1.cob:3: error: object-oriented COBOL is not supported 
-prog1.cob:4: error: syntax error, unexpected ., expecting class-name or Literal
+[prog1.cob:3: error: object-oriented COBOL is not supported
+prog1.cob:4: error: syntax error, unexpected ., expecting class-name
 ])
 
 AT_DATA([prog2.cob], [
@@ -62,18 +62,23 @@ AT_DATA([prog2.cob], [
 
 AT_CHECK([$COMPILE_ONLY prog2.cob], [1], [],
 [prog2.cob:3: error: object-oriented COBOL is not supported
-prog2.cob:4: error: syntax error, unexpected END PROGRAM, expecting END CLASS
+prog2.cob:4: error: syntax error, unexpected END PROGRAM, expecting FACTORY or OBJECT
 ])
 
 AT_DATA([prog3.cob], [
         IDENTIFICATION DIVISION.
         CLASS-ID. MyFirstClass.
         END CLASS MyClass.
+
+        INTERFACE-ID. MyFirstInterface.
+        END INTERFACE MyInterface.
 ])
 
 AT_CHECK([$COMPILE_ONLY prog3.cob], [1], [],
 [prog3.cob:3: error: object-oriented COBOL is not supported
 prog3.cob:4: error: END CLASS 'MyClass' is different from CLASS-ID 'MyFirstClass'
+prog3.cob:6: error: object-oriented COBOL (INTERFACE) is not supported
+prog3.cob:7: error: END INTERFACE 'MyInterface' is different from INTERFACE-ID 'MyFirstInterface'
 ])
 
 AT_CLEANUP
@@ -93,8 +98,8 @@ AT_DATA([prog.cob], [
 
 AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
 [prog.cob:3: error: object-oriented COBOL is not supported
-prog.cob:6: error: redefinition of class ID 'MyClass'
 prog.cob:6: error: object-oriented COBOL is not supported
+prog.cob:6: error: redefinition of class ID 'MyClass'
 ])
 AT_CLEANUP
 
@@ -109,16 +114,29 @@ AT_DATA([prog.cob], [
 
         CLASS-ID. DematAccount.
         END CLASS DematAccount.
-        
+
         CLASS-ID. SavingsAccount INHERITS FROM Account.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Account.
         END CLASS SavingsAccount.
 
         *> Skips optional FROM keyword for INHERITS attribute
         CLASS-ID. MinorSavingsAccount INHERITS SavingsAccount.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS SavingsAccount.
         END CLASS MinorSavingsAccount.
 
         CLASS-ID. MultiPurposeAccount INHERITS
                   FROM Account DematAccount.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Account
+            CLASS DematAccount.
         END CLASS MultiPurposeAccount.
 
         CLASS-ID. MyAccount USING startingBalance.
@@ -129,9 +147,9 @@ AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
 [prog.cob:3: error: object-oriented COBOL is not supported
 prog.cob:6: error: object-oriented COBOL is not supported
 prog.cob:9: error: object-oriented COBOL is not supported
-prog.cob:13: error: object-oriented COBOL is not supported
-prog.cob:16: error: object-oriented COBOL is not supported
-prog.cob:20: error: object-oriented COBOL is not supported
+prog.cob:17: error: object-oriented COBOL is not supported
+prog.cob:24: error: object-oriented COBOL is not supported
+prog.cob:33: error: object-oriented COBOL is not supported
 ])
 AT_CLEANUP
 
@@ -143,18 +161,26 @@ AT_DATA([prog.cob], [
         IDENTIFICATION DIVISION.
         CLASS-ID. MySuperClass.
         END CLASS MySuperClass.
-        
-        CLASS-ID. MyFirstClass INHERITS 
+
+        CLASS-ID. MyFirstClass INHERITS
                   FROM MySuperClass IS FINAL.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS MySuperClass.
         END CLASS MyFirstClass.
 
-        CLASS-ID. MySecondClass AS "MySecondClass" 
+        CLASS-ID. MySecondClass AS "MySecondClass"
                   IS FINAL.
         END CLASS MySecondClass.
 
-        CLASS-ID. MyThirdClass 
+        CLASS-ID. MyThirdClass
                   INHERITS FROM MySuperClass
                   USING param-name.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS MySuperClass.
         END CLASS MyThirdClass.
 
         *> Skips optional IS keyword for FINAL attribute
@@ -166,9 +192,9 @@ AT_DATA([prog.cob], [
 AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
 [prog.cob:3: error: object-oriented COBOL is not supported
 prog.cob:6: error: object-oriented COBOL is not supported
-prog.cob:10: error: object-oriented COBOL is not supported
-prog.cob:15: error: object-oriented COBOL is not supported
-prog.cob:20: error: object-oriented COBOL is not supported
+prog.cob:14: error: object-oriented COBOL is not supported
+prog.cob:18: error: object-oriented COBOL is not supported
+prog.cob:28: error: object-oriented COBOL is not supported
 ])
 AT_CLEANUP
 
@@ -184,33 +210,51 @@ AT_DATA([prog.cob], [
         CLASS-ID. DematAccount INHERITS Account
                   ABSTRACT
                   IS PUBLIC.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Account.
         END CLASS DematAccount.
-        
-        CLASS-ID. SavingsAccount 
+
+        CLASS-ID. SavingsAccount
                   INHERITS FROM Account
                   FINAL.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Account.
         END CLASS SavingsAccount.
 
         CLASS-ID. MinorSavingsAccount
                   INHERITS SavingsAccount
                   IS INTERNAL.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS SavingsAccount.
         END CLASS MinorSavingsAccount.
 
-        CLASS-ID. MultiPurposeAccount 
+        CLASS-ID. MultiPurposeAccount
                   INHERITS Account DematAccount
                   PARTIAL.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Account
+            CLASS DematAccount.
         END CLASS MultiPurposeAccount.
 ])
 
 AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
 [prog.cob:3: error: object-oriented COBOL is not supported
 prog.cob:6: error: object-oriented COBOL is not supported
-prog.cob:12: error: object-oriented COBOL is not supported
-prog.cob:17: error: object-oriented COBOL is not supported
-prog.cob:22: error: object-oriented COBOL is not supported
+prog.cob:15: error: object-oriented COBOL is not supported
+prog.cob:24: error: object-oriented COBOL is not supported
+prog.cob:33: error: object-oriented COBOL is not supported
 ])
 AT_CLEANUP
 
+
 AT_SETUP([CLASS-ID Attribute Error Check])
 AT_KEYWORDS([OOP])
 
@@ -224,18 +268,31 @@ AT_DATA([prog.cob], [
                   ABSTRACT
                   IS PUBLIC
                   INTERNAL.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Account.
         END CLASS DematAccount.
-        
-        CLASS-ID. SavingsAccount 
+
+        CLASS-ID. SavingsAccount
                   INHERITS FROM Account
                   FINAL
                   IS ABSTRACT.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Account.
         END CLASS SavingsAccount.
 
-        CLASS-ID. MultiPurposeAccount 
+        CLASS-ID. MultiPurposeAccount
                   INHERITS Account DematAccount
                   PARTIAL
                   IS PARTIAL.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Account
+            CLASS DematAccount.
         END CLASS MultiPurposeAccount.
 ])
 
@@ -244,9 +301,515 @@ AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
 prog.cob:4: error: duplicate FINAL clause
 prog.cob:7: error: object-oriented COBOL is not supported
 prog.cob:10: error: cannot specify both INTERNAL and PUBLIC
-prog.cob:14: error: object-oriented COBOL is not supported
-prog.cob:16: error: cannot specify both FINAL and ABSTRACT
-prog.cob:20: error: object-oriented COBOL is not supported
-prog.cob:22: error: duplicate PARTIAL clause
+prog.cob:17: error: object-oriented COBOL is not supported
+prog.cob:20: error: cannot specify both FINAL and ABSTRACT
+prog.cob:27: error: object-oriented COBOL is not supported
+prog.cob:30: error: duplicate PARTIAL clause
+])
+AT_CLEANUP
+
+
+AT_SETUP([INTERFACE-ID syntax check])
+AT_KEYWORDS([OOP])
+
+AT_DATA([prog.cob], [
+        IDENTIFICATION DIVISION.
+
+        INTERFACE-ID. Account.
+        END INTERFACE Account.
+
+        INTERFACE-ID. DematAccount
+                    INHERITS Account
+                    USING param-name.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            INTERFACE Account.
+        END INTERFACE DematAccount.
+])
+
+AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
+[prog.cob:4: error: object-oriented COBOL (INTERFACE) is not supported
+prog.cob:7: error: object-oriented COBOL (INTERFACE) is not supported
+])
+AT_CLEANUP
+
+
+AT_SETUP([CLASS specifier in REPOSITORY paragraph])
+AT_KEYWORDS([OOP])
+
+AT_DATA([prog.cob], [
+        IDENTIFICATION DIVISION.
+
+        CLASS-ID. Account IS FINAL.
+        END CLASS Account.
+
+        CLASS-ID. SavingsAccount
+            INHERITS ACCOUNT
+            IS FINAL.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Account AS "Account".
+        END CLASS SavingsAccount.
+])
+
+AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
+[prog.cob:4: error: object-oriented COBOL is not supported
+prog.cob:7: error: object-oriented COBOL is not supported
+])
+AT_CLEANUP
+
+
+AT_SETUP([CLASS-ID and INTERFACE-ID Syntax Checks])
+AT_KEYWORDS([OOP])
+
+AT_DATA([prog1.cob], [
+        IDENTIFICATION DIVISION.
+        INTERFACE-ID. MyFactoryInterface.
+        END INTERFACE MyFactoryInterface.
+
+        INTERFACE-ID. MyInterface.
+        END INTERFACE MyInterface.
+
+        CLASS-ID. MyBaseClass.
+        FACTORY.
+                IMPLEMENTS MyFactoryInterface.
+        END FACTORY.
+        OBJECT.
+                DATA DIVISION.
+                WORKING-STORAGE SECTION.
+                    01 data-name PIC 9(2).
+                PROCEDURE DIVISION.
+                METHOD-ID. MyMethod IS FINAL.
+                END METHOD MyMethod.
+
+                METHOD-ID. GET PROPERTY data-name.
+                END METHOD.
+
+                METHOD-ID. SET PROPERTY data-name.
+                END METHOD.
+        END OBJECT.
+        END CLASS MyBaseClass.
+
+        CLASS-ID. MyDerivedClass
+        INHERITS FROM MyBaseClass
+                        MyBaseClass
+                        MyUnknownClass
+                        MyDerivedClass.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+                CLASS MyBaseClass AS "MyKnownClass"
+                INTERFACE MyInterface.
+        FACTORY.
+        END FACTORY.
+        END CLASS MyDerivedClass.
+])
+
+AT_CHECK([$COMPILE_ONLY prog1.cob], [1], [],
+[prog1.cob:3: error: object-oriented COBOL (INTERFACE) is not supported
+prog1.cob:6: error: object-oriented COBOL (INTERFACE) is not supported
+prog1.cob:9: error: object-oriented COBOL is not supported
+prog1.cob:29: error: object-oriented COBOL is not supported
+prog1.cob:37: warning: no definition/prototype seen for CLASS with external name 'MyKnownClass'
+prog1.cob:31: error: duplicate parent CLASS 'MyBaseClass'
+prog1.cob:30: note: 'MyBaseClass' defined here
+prog1.cob:32: error: inherited CLASS 'MyUnknownClass' not found in REPOSITORY paragraph
+prog1.cob:33: error: cyclically inheriting CLASS 'MyDerivedClass'
+prog1.cob:29: note: 'MyDerivedClass' defined here
+prog1.cob:33: error: inherited CLASS 'MyDerivedClass' not found in REPOSITORY paragraph
+prog1.cob:31: error: duplicate parent CLASS 'MyBaseClass'
+prog1.cob:30: note: 'MyBaseClass' defined here
+prog1.cob:32: error: inherited CLASS 'MyUnknownClass' not found in REPOSITORY paragraph
+prog1.cob:33: error: cyclically inheriting CLASS 'MyDerivedClass'
+prog1.cob:29: note: 'MyDerivedClass' defined here
+prog1.cob:33: error: inherited CLASS 'MyDerivedClass' not found in REPOSITORY paragraph
+])
+
+AT_DATA([prog2.cob], [
+        IDENTIFICATION DIVISION.
+        INTERFACE-ID. MyInterface.
+        END INTERFACE MyInterface.
+
+        INTERFACE-ID. MyBaseInterface.
+        END INTERFACE MyBaseInterface.
+
+        INTERFACE-ID. MyDerivedInterface
+        INHERITS FROM MyBaseInterface
+                      MyBaseInterface
+                      MyUnknownInterface
+                      MyDerivedInterface.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+                INTERFACE MyBaseInterface AS "MyKnownInterface"
+                EXPANDS MyInterface
+                USING dummy-param.
+        END INTERFACE MyDerivedInterface.
+])
+AT_CHECK([$COMPILE_ONLY prog2.cob], [1], [],
+[prog2.cob:3: error: object-oriented COBOL (INTERFACE) is not supported
+prog2.cob:6: error: object-oriented COBOL (INTERFACE) is not supported
+prog2.cob:9: error: object-oriented COBOL (INTERFACE) is not supported
+prog2.cob:17: warning: no definition/prototype seen for INTERFACE with external name 'MyKnownInterface'
+prog2.cob:11: error: duplicate parent INTERFACE 'MyBaseInterface'
+prog2.cob:10: note: 'MyBaseInterface' defined here
+prog2.cob:12: error: inherited INTERFACE 'MyUnknownInterface' not found in REPOSITORY paragraph
+prog2.cob:13: error: cyclically inheriting INTERFACE 'MyDerivedInterface'
+prog2.cob:9: note: 'MyDerivedInterface' defined here
+prog2.cob:13: error: inherited INTERFACE 'MyDerivedInterface' not found in REPOSITORY paragraph
 ])
+
+AT_CLEANUP
+
+
+AT_SETUP([INVOKE statement])
+AT_KEYWORDS([OOP])
+
+AT_DATA([prog.cob], [
+        IDENTIFICATION DIVISION.
+        INTERFACE-ID. MyFactoryInterface.
+        END INTERFACE MyFactoryInterface.
+
+        CLASS-ID. MyBaseClass.
+        FACTORY.
+                IMPLEMENTS MyFactoryInterface.
+            PROCEDURE DIVISION.
+            METHOD-ID. MyMethod IS FINAL.
+                PROCEDURE DIVISION.
+                    DISPLAY "Hello, world!".
+            END METHOD MyMethod.
+        END FACTORY.
+        END CLASS MyBaseClass.
+
+        PROGRAM-ID. prog.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS MyBaseClass AS "MyClass".
+        DATA DIVISION.
+        WORKING-STORAGE SECTION.
+            01 an-object USAGE OBJECT REFERENCE MyBaseClass.
+            01 a-factory USAGE OBJECT REFERENCE FACTORY OF ACTIVE-CLASS.
+
+        PROCEDURE DIVISION.
+            INVOKE MyBaseClass "MyMethod".
+            INVOKE an-object "MyMethod".
+            INVOKE a-factory "StaticMethod".
+        END PROGRAM prog.
+])
+
+AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
+[prog.cob:3: error: object-oriented COBOL (INTERFACE) is not supported
+prog.cob:6: error: object-oriented COBOL is not supported
+prog.cob:21: warning: no definition/prototype seen for CLASS with external name 'MyClass'
+])
+AT_CLEANUP
+
+
+AT_SETUP([Simple OO Example (Accounts)])
+AT_KEYWORDS([OOP])
+
+AT_DATA([prog.cob], [
+        IDENTIFICATION DIVISION.
+        CLASS-ID. Account INHERITS Base.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS Base.
+
+        FACTORY.
+        DATA DIVISION.
+        WORKING-STORAGE SECTION.
+        01 number-of-accounts PIC 9(5) VALUE ZERO.
+        PROCEDURE DIVISION.
+        METHOD-ID. newAccount.
+        DATA DIVISION.
+        WORKING-STORAGE SECTION.
+            01 an-object USAGE IS OBJECT REFERENCE ACTIVE-CLASS.
+        PROCEDURE DIVISION RETURNING an-object.
+            begin-here.
+            INVOKE SELF "new" RETURNING an-object.
+            INVOKE an-object "initializeAccount"
+                    USING BY CONTENT number-of-accounts.
+            GOBACK.
+            END METHOD newAccount.
+            METHOD-ID. addAccount.
+            PROCEDURE DIVISION.
+                method-start.
+                ADD 1 TO number-of-accounts.
+                GOBACK.
+            END METHOD addAccount.
+            METHOD-ID. removeAccount.
+            PROCEDURE DIVISION.
+                main-entry.
+                SUBTRACT 1 FROM number-of-accounts.
+                GOBACK.
+            END METHOD removeAccount.
+        END FACTORY.
+
+        OBJECT.
+        DATA DIVISION.
+        WORKING-STORAGE SECTION.
+            01 account-balance PIC S9(9)V99.
+            01 account-number PIC X(9).
+            01 the-date PIC 9(8).
+        PROCEDURE DIVISION.
+            METHOD-ID. displayUI.
+            DATA DIVISION.
+            LOCAL-STORAGE SECTION.
+                01 in-data.
+                    03 action-type PIC X.
+                    03 in-amount PIC S9(9)V99.
+                    03 in-wrk PIC X(12).
+            PROCEDURE DIVISION.
+
+            get-amount.
+            DISPLAY "Enter amount 9(9).99"
+            ACCEPT in-wrk
+            COMPUTE in-amount = FUNCTION NUMVAL (in-wrk)
+            .
+            END METHOD displayUI.
+            METHOD-ID. balance.
+            DATA DIVISION.
+            LOCAL-STORAGE SECTION.
+                01 display-balance PIC $ZZZ,ZZZ,ZZ9.99B-.
+            PROCEDURE DIVISION.
+            disp-balance.
+            MOVE account-balance to display-balance
+            DISPLAY "Your Account Balance is:" display-balance
+            GOBACK.
+            END METHOD balance.
+            METHOD-ID. deposit.
+                DATA DIVISION.
+                LINKAGE SECTION.
+                    01 in-deposit PIC S9(9)V99.
+                PROCEDURE DIVISION USING in-deposit.
+                make-deposit.
+                ADD in-deposit TO account-balance
+                GOBACK.
+            END METHOD deposit.
+            METHOD-ID. withdraw.
+            DATA DIVISION.
+            LINKAGE SECTION.
+                01 in-withdraw PIC S9(9)V99.
+            PROCEDURE DIVISION USING in-withdraw.
+            withdraw-start.
+            IF account-balance >= in-withdraw
+                SUBTRACT in-withdraw FROM account-balance
+            ELSE
+                DISPLAY "Your Balance is Inadequate"
+            END-IF
+            GOBACK.
+            END METHOD withdraw.
+            METHOD-ID. initializeAccount.
+            DATA DIVISION.
+            LINKAGE SECTION.
+                01 new-account-number PIC 9(5).
+            PROCEDURE DIVISION USING new-account-number.
+                Begin-initialization.
+                MOVE ZERO TO account-balance
+                MOVE new-account-number TO account-number
+                MOVE FUNCTION CURRENT-DATE (1: 8) TO the-date
+                GOBACK.
+            END METHOD initializeAccount.
+        END OBJECT.
+        END CLASS Account.
+])
+
+AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
+[prog.cob:3: error: object-oriented COBOL is not supported
+prog.cob:7: warning: no definition/prototype seen for CLASS 'Base'
+prog.cob:18: error: RETURNING item is not defined in LINKAGE SECTION
+prog.cob: in paragraph 'begin-here':
+prog.cob:22: error: 'number-of-accounts' is not defined
+prog.cob: in paragraph 'method-start':
+prog.cob:28: error: 'number-of-accounts' is not defined
+prog.cob: in paragraph 'main-entry':
+prog.cob:34: error: 'number-of-accounts' is not defined
+prog.cob: in paragraph 'disp-balance':
+prog.cob:67: error: 'account-balance' is not defined
+prog.cob: in paragraph 'make-deposit':
+prog.cob:77: error: 'account-balance' is not defined
+prog.cob: in paragraph 'withdraw-start':
+prog.cob:86: error: 'account-balance' is not defined
+prog.cob: in paragraph 'Begin-initialization':
+prog.cob:99: error: 'account-balance' is not defined
+prog.cob:100: error: 'account-number' is not defined
+prog.cob:101: error: 'the-date' is not defined
+])
+AT_CLEANUP
+
+
+AT_SETUP([Inline method invocation expression])
+AT_KEYWORDS([OOP])
+
+AT_DATA([prog.cob], [
+        IDENTIFICATION DIVISION.
+        CLASS-ID. MyBaseClass AS "MyClass".
+        FACTORY.
+            PROCEDURE DIVISION.
+            METHOD-ID. MyMethod IS FINAL.
+                DATA DIVISION.
+                LINKAGE SECTION.
+                    01 VAR-IN  PIC 9(2).
+                    01 VAR-OUT  PIC 9(2).
+                PROCEDURE DIVISION USING VAR-IN
+                        RETURNING VAR-OUT.
+                    MOVE VAR-IN TO VAR-OUT.
+                    DISPLAY "Hello, world!".
+            END METHOD MyMethod.
+        END FACTORY.
+        OBJECT.
+            PROCEDURE DIVISION.
+            METHOD-ID. SayHello.
+                ENVIRONMENT DIVISION.
+                CONFIGURATION SECTION.
+                REPOSITORY.
+                    CLASS MyBaseClass AS "MyClass".
+                DATA DIVISION.
+                WORKING-STORAGE SECTION.
+                    01 an-object USAGE OBJECT REFERENCE MyBaseClass.
+                    01 a-var PIC 9(2).
+                PROCEDURE DIVISION.
+                    DISPLAY an-object :: "MyMethod" (10).
+                    DISPLAY an-object :: "MyMethod" ().
+                    DISPLAY an-object :: "MyMethod" (10 + 2).
+                    DISPLAY an-object :: "MyMethod" (10 + 2, 42).
+                    DISPLAY an-object :: "MyMethod" (OMITTED).
+                    DISPLAY an-object :: "MyMethod" (OMITTED, 42).
+                    MOVE 98 TO a-var.
+                    DISPLAY an-object :: "MyMethod" (a-var).
+                    DISPLAY SELF.
+                    DISPLAY SELF :: "MyMethod" (a-var).
+                    INVOKE an-object "MyMethod" USING SUPER.
+            END METHOD SayHello.
+        END OBJECT.
+        END CLASS MyBaseClass.
+
+        PROGRAM-ID. prog.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS MyBaseClass AS "MyClass".
+        DATA DIVISION.
+        WORKING-STORAGE SECTION.
+            01 an-object USAGE OBJECT REFERENCE MyBaseClass.
+            01 a-var PIC 9(2).
+
+        PROCEDURE DIVISION.
+            DISPLAY an-object :: "MyMethod" (10).
+            DISPLAY an-object :: "MyMethod" (10 + 2).
+            MOVE 98 TO a-var.
+            DISPLAY an-object :: "MyMethod" (a-var).
+            DISPLAY an-object :: "SayHello".
+
+            INVOKE an-object "SayHello" USING 1.
+            INVOKE an-object "MyMethod" USING SUPER.
+
+            MOVE SELF TO an-object.
+            MOVE SUPER TO an-object.
+        END PROGRAM prog.
+])
+
+AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
+[prog.cob:3: error: object-oriented COBOL is not supported
+prog.cob:30: warning: argument #1 is not optional
+prog.cob:32: warning: expecting up to 1 arguments, but found 2
+prog.cob:33: warning: argument #1 is not optional
+prog.cob:34: warning: argument #1 is not optional
+prog.cob:34: warning: expecting up to 1 arguments, but found 2
+prog.cob:37: error: 'MyBaseClass' is an invalid type for DISPLAY operand
+prog.cob:39: warning: expecting a RETURNING item, but none provided
+prog.cob:59: warning: invalid inline invocation of a method with no RETURNING
+prog.cob:61: warning: expecting up to 0 arguments, but found 1
+prog.cob:62: error: use of SUPER outside of METHOD definition
+prog.cob:62: warning: expecting a RETURNING item, but none provided
+prog.cob:64: error: use of SELF outside of METHOD definition
+prog.cob:65: error: use of SUPER outside of METHOD definition
+])
+AT_CLEANUP
+
+
+AT_SETUP([SUPER in multiple inheritance context])
+AT_KEYWORDS([OOP])
+
+AT_DATA([prog.cob], [
+        CLASS-ID. A.
+        OBJECT.
+        PROCEDURE DIVISION.
+        METHOD-ID. M.
+        END METHOD M.
+        END OBJECT.
+        END CLASS A.
+
+        CLASS-ID. B.
+        OBJECT.
+        PROCEDURE DIVISION.
+        METHOD-ID. M.
+        END METHOD M.
+        END OBJECT.
+        END CLASS B.
+
+        CLASS-ID. C INHERITS A B.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+          CLASS A
+          CLASS B.
+        OBJECT.
+        PROCEDURE DIVISION.
+        METHOD-ID. M.
+        PROCEDURE DIVISION.
+           INVOKE SUPER "M"
+           GOBACK.
+        END METHOD M.
+        END OBJECT.
+        END CLASS C.
+])
+AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
+[prog.cob:2: error: object-oriented COBOL is not supported
+prog.cob:10: error: object-oriented COBOL is not supported
+prog.cob:18: error: object-oriented COBOL is not supported
+prog.cob:28: warning: use of SUPER in CLASS or INTERFACE with multiple inheritance may be ambiguous
+])
+
+AT_CLEANUP
+
+
+AT_SETUP([Wrong CLASS prototype])
+AT_KEYWORDS([OOP])
+
+AT_DATA([prog.cob], [
+        FUNCTION-ID. fun.
+        DATA DIVISION.
+        LINKAGE SECTION.
+        77 X PIC 9.
+        PROCEDURE DIVISION RETURNING X.
+             MOVE 0 TO X
+             GOBACK.
+        END FUNCTION fun.
+
+        PROGRAM-ID. prog.
+        ENVIRONMENT DIVISION.
+        CONFIGURATION SECTION.
+        REPOSITORY.
+            CLASS C AS "fun".
+        DATA DIVISION.
+        WORKING-STORAGE SECTION.
+            01 O USAGE OBJECT REFERENCE C.
+        PROCEDURE DIVISION.
+            INVOKE C "MyMethod".
+            INVOKE O "MyMethod".
+        END PROGRAM prog.
+])
+
+AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
+[prog.cob:15: error: CLASS REPOSITORY entry for 'fun' does not match its definition
+prog.cob:15: note: 'fun' defined as a FUNCTION here
+prog.cob:20: error: CLASS or INTERFACE expected (got FUNCTION 'fun')
+prog.cob:21: error: CLASS or INTERFACE expected (got FUNCTION 'fun')
+])
+
 AT_CLEANUP
diff --git a/tests/testsuite.src/syn_screen.at b/tests/testsuite.src/syn_screen.at
index ec3c4de5a..1221dba88 100644
--- a/tests/testsuite.src/syn_screen.at
+++ b/tests/testsuite.src/syn_screen.at
@@ -808,8 +808,8 @@ AT_DATA([prog.cob], [
 AT_CHECK([$COMPILE_ONLY prog.cob], [1], [],
 [prog.cob:10: error: 'LIN' is not defined
 prog.cob:10: error: syntax error, unexpected COL
-prog.cob:11: error: syntax error, unexpected COL, expecting Literal or [)] or Identifier
-prog.cob:12: error: syntax error, unexpected COL, expecting Literal or [)] or Identifier
+prog.cob:11: error: syntax error, unexpected COL
+prog.cob:12: error: syntax error, unexpected COL
 prog.cob:19: error: syntax error, unexpected COL
 prog.cob:20: error: syntax error, unexpected COL
 ])