diff --git a/repository/src/main/resources/xsd/repository.xsd b/repository/src/main/resources/xsd/repository.xsd
index e94c6bc..099c8e6 100644
--- a/repository/src/main/resources/xsd/repository.xsd
+++ b/repository/src/main/resources/xsd/repository.xsd
@@ -63,6 +63,10 @@
 						<xs:selector xpath="fixr:code"/>
 						<xs:field xpath="@name"/>
 					</xs:key>
+					<xs:key name="codeIdKey">
+						<xs:selector xpath="fixr:code"/>
+						<xs:field xpath="@id"/>
+					</xs:key>
 				</xs:element>
 				<xs:element ref="fixr:encodings" minOccurs="0"/>
 				<xs:element name="annotation" type="fixr:annotation" minOccurs="0"/>