diff --git a/apps/emqx/src/emqx_trace/emqx_trace.erl b/apps/emqx/src/emqx_trace/emqx_trace.erl
index 37b9d4ab5..99bbcc5f9 100644
--- a/apps/emqx/src/emqx_trace/emqx_trace.erl
+++ b/apps/emqx/src/emqx_trace/emqx_trace.erl
@@ -87,13 +87,8 @@ log(List, Msg, Meta) ->
     log(debug, List, Msg, Meta).
 
 log(Level, List, Msg, Meta) ->
-    Log = #{level => Level, meta => enrich_meta(Meta)},
-    Log1 =
-        case Msg of
-            undefined -> Log;
-            _ -> maps:put(msg, Msg, Log)
-        end,
-    log_filter(List, Log1).
+    Log = #{level => Level, meta => enrich_meta(Meta), msg => Msg},
+    log_filter(List, Log).
 
 enrich_meta(Meta) ->
     case logger:get_process_metadata() of