diff --git a/src/erf_http_server/erf_http_server_elli.erl b/src/erf_http_server/erf_http_server_elli.erl
index d28fce7..9b34808 100644
--- a/src/erf_http_server/erf_http_server_elli.erl
+++ b/src/erf_http_server/erf_http_server_elli.erl
@@ -293,6 +293,8 @@ postprocess(
             <<>>, erlang:self(), undefined, {undefined, []}}
     ),
     {Status, Headers, {file, File, Range}};
+postprocess(_Request, {Status, RawHeaders, undefined}) ->
+    {Status, RawHeaders, []};
 postprocess(_Request, {Status, RawHeaders, RawBody}) ->
     {Status, RawHeaders, RawBody}.
 
diff --git a/src/erf_router.erl b/src/erf_router.erl
index 22676b4..f7ceaa1 100644
--- a/src/erf_router.erl
+++ b/src/erf_router.erl
@@ -890,7 +890,7 @@ postprocess(_Request, {Status, RawHeaders, RawBody}) ->
         undefined ->
             case RawBody of
                 undefined ->
-                    {Status, RawHeaders, []};
+                    {Status, RawHeaders, undefined};
                 _RawBody ->
                     try iolist_to_binary(json:encode(RawBody)) of
                         EncodedBody ->