diff --git a/apps/emqx_rule_engine/src/emqx_rule_metrics.erl b/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
index 7b1fe2f54..ed831bc3b 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
@@ -326,8 +326,9 @@ handle_info(_Info, State) ->
 
 code_change({down, _Vsn}, State = #state{metric_ids = MIDs}, [Vsn]) ->
     case string:tokens(Vsn, ".") of 
-        ["4", "3", Val] ->
-            case string:to_integer(Val) =< 7 of
+        ["4", "3", SVal] ->
+            {Val, []} = string:to_integer(SVal),
+            case Val  =< 7 of
                 true ->
                     [begin
                         Passed = get_rules_passed(Id),
@@ -353,8 +354,9 @@ code_change({down, _Vsn}, State = #state{metric_ids = MIDs}, [Vsn]) ->
 
 code_change(_Vsn, State = #state{metric_ids = MIDs}, [Vsn]) ->
     case string:tokens(Vsn, ".") of
-        ["4", "3", Val] ->
-            case string:to_integer(Val) =< 7 of
+        ["4", "3", SVal] ->
+            {Val, []} = string:to_integer(SVal),
+            case Val =< 7 of
                 true ->
                     [begin
                         Matched = get_rules_matched(Id),