diff --git a/src/Effects/Time.hs b/src/Effects/Time.hs
index ca51046..845c910 100644
--- a/src/Effects/Time.hs
+++ b/src/Effects/Time.hs
@@ -36,8 +36,4 @@ runTimeEff = interpret $ \env -> \case
   CurrentTimeT ->
     encode_YmdHMS (SubsecondPrecisionFixed 4) w3c . timeToDatetime
       <$> liftIO now
-  BenchFunction f -> do
-    s <- liftIO now
-    !d <- localSeqUnlift env $ \unlift -> unlift f
-    e <- liftIO now
-    pure (C.width $ s ... e, d)
+  BenchFunction f -> localSeqUnliftIO env $ \run -> stopwatch . run $ f