diff --git a/store/tikv/2pc.go b/store/tikv/2pc.go
index 6f6409a758..a5ce182fe8 100644
--- a/store/tikv/2pc.go
+++ b/store/tikv/2pc.go
@@ -1588,6 +1588,6 @@ func (batchExe *batchExecutor) process(batches []batchMutations) error {
 		}
 	}
 	close(exitCh)
-	metrics.TiKVTokenWaitDuration.Observe(float64(batchExe.tokenWaitDuration))
+	metrics.TiKVTokenWaitDuration.Observe(batchExe.tokenWaitDuration.Seconds())
 	return err
 }