diff --git a/apps/emqx_rule_engine/src/emqx_rule_metrics.erl b/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
index 53bfd9bb5..0f8e1a7f4 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
@@ -35,7 +35,6 @@
         , get_rules_passed/1
         , get_rules_exception/1
         , get_rules_no_result/1
-        
         ]).
 
 -export([ inc_rules_matched/2