diff --git a/src/jesse_lib.erl b/src/jesse_lib.erl
index 4c037739..2d9014df 100644
--- a/src/jesse_lib.erl
+++ b/src/jesse_lib.erl
@@ -239,7 +239,7 @@ compare_properties(Value1, Value2) ->
 %% @doc Returns "id" or "$id" based on the value of $schema.
 -spec get_schema_id_key(Schema :: jesse:json_term()) -> binary().
 get_schema_id_key(Schema) ->
-  case jesse_json_path:value(?SCHEMA, Schema, undefined) of
+  case jesse_json_path:value(?SCHEMA, Schema, ?default_schema_ver) of
     ?json_schema_draft6 -> ?ID;
                       _ -> ?ID_OLD
   end.