diff --git a/limit.go b/limit.go
index f00657d..ab303ad 100644
--- a/limit.go
+++ b/limit.go
@@ -38,6 +38,9 @@ func (o *WindowsLimitOption) Default() {
 	if o.Size <= 0 {
 		o.Size = time.Second * 60
 	}
+
+	o.failKey = o.Key + ":fail"
+	o.succKey = o.Key + ":succ"
 }
 func (w *WindowsLimit) tidy() {
 	now := time.Now().UnixMilli()