diff --git a/apps/emqx_utils/src/emqx_variform_parser.yrl b/apps/emqx_utils/src/emqx_variform_parser.yrl
index 8a8a03a4d..508ef46d0 100644
--- a/apps/emqx_utils/src/emqx_variform_parser.yrl
+++ b/apps/emqx_utils/src/emqx_variform_parser.yrl
@@ -36,3 +36,8 @@ arg -> expr : '$1'.
 arg -> array : '$1'.
 arg -> number : {num, element(3, '$1')}.
 arg -> string : {str, element(3, '$1')}.
+
+Erlang code.
+
+%% mute xref warning
+-export([return_error/2]).