diff --git a/net/middleware/throttler/index.go b/net/middleware/throttler/index.go
index 2393921..cf70850 100644
--- a/net/middleware/throttler/index.go
+++ b/net/middleware/throttler/index.go
@@ -90,5 +90,5 @@ func (c *Controller) Expire(id string) time.Duration {
 	if since > 0 {
 		return 0
 	}
-	return since
+	return -since
 }