diff --git a/limit.go b/limit.go
index 6fe2906..4739bce 100644
--- a/limit.go
+++ b/limit.go
@@ -20,21 +20,25 @@ type WindowsLimit struct {
 	option *WindowsLimitOption
 }
 
-func NewWindowsLimitOption() *WindowsLimitOption {
-	return &WindowsLimitOption{
-		Key:   fmt.Sprintf("windows:limit:%s:%d", time.Now().Format("20060102"), time.Now().UnixMilli()),
-		Count: 1000,
-		Size:  time.Second * 60,
-	}
-}
-
 func NewWindowsLimit(client *redis.Client, option *WindowsLimitOption) *WindowsLimit {
+	option.Default()
 	return &WindowsLimit{
 		client: client,
 		option: option,
 	}
 }
 
+func (o *WindowsLimitOption) Default() {
+	if o.Key == "" {
+		o.Key = fmt.Sprintf("windows:limit:%s:%d", time.Now().Format("20060102"), time.Now().UnixMilli())
+	}
+	if o.Count <= 0 {
+		o.Count = 1000
+	}
+	if o.Size <= 0 {
+		o.Size = time.Second * 60
+	}
+}
 func (w *WindowsLimit) tidy() {
 	now := time.Now().UnixMilli()
 	start := now - w.option.Size.Milliseconds()