diff --git a/apps/emqx_auth_http/src/emqx_acl_http.erl b/apps/emqx_auth_http/src/emqx_acl_http.erl
index a6f60b465..23588fe9a 100644
--- a/apps/emqx_auth_http/src/emqx_acl_http.erl
+++ b/apps/emqx_auth_http/src/emqx_acl_http.erl
@@ -36,6 +36,7 @@
 
 -spec(register_metrics() -> ok).
 register_metrics() ->
+    io:format("testing"),
     lists:foreach(fun emqx_metrics:ensure/1, ?ACL_METRICS).
 
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