diff --git a/apps/emqx/src/emqx_trace/emqx_trace.erl b/apps/emqx/src/emqx_trace/emqx_trace.erl
index 9e57b778a..988c2b808 100644
--- a/apps/emqx/src/emqx_trace/emqx_trace.erl
+++ b/apps/emqx/src/emqx_trace/emqx_trace.erl
@@ -255,9 +255,11 @@ format(Traces) ->
         fun(Trace0 = #?TRACE{}) ->
             [_ | Values] = tuple_to_list(Trace0),
             Map0 = maps:from_list(lists:zip(Fields, Values)),
-            Extra = maps:get(extra, Map0, #{}),
-            Formatter = maps:get(formatter, Extra, text),
-            Map0#{formatter => Formatter}
+            Extra0 = maps:get(extra, Map0, #{}),
+            Formatter = maps:get(formatter, Extra0, text),
+            Map1 = Map0#{formatter => Formatter},
+            Extra1 = maps:remove(formatter, Extra0),
+            maps:put(extra, Extra1, Map1)
         end,
         Traces
     ).