diff --git a/inc/framework/omg/parser/parser_types.h b/inc/framework/omg/parser/parser_types.h
index f3b7f00a..429a39d1 100644
--- a/inc/framework/omg/parser/parser_types.h
+++ b/inc/framework/omg/parser/parser_types.h
@@ -461,6 +461,9 @@ FMK_FUNC_HOST_VISIBILITY FMK_FUNC_DEV_VISIBILITY extern const char *HVDCALLBACKA
 FMK_FUNC_HOST_VISIBILITY FMK_FUNC_DEV_VISIBILITY extern const char *HVDCALLBACKBROADCAST;
 FMK_FUNC_HOST_VISIBILITY FMK_FUNC_DEV_VISIBILITY extern const char *HVDWAIT;
 
+// Onnx output operator
+FMK_FUNC_HOST_VISIBILITY FMK_FUNC_DEV_VISIBILITY extern const char *_RETVAL;
+
 ///
 /// @brief Magic number of model file
 ///