diff --git a/gorush/notification.go b/gorush/notification.go
index 36182d2..3f77a99 100644
--- a/gorush/notification.go
+++ b/gorush/notification.go
@@ -81,7 +81,7 @@ type PushNotification struct {
 	Notification          fcm.Notification `json:"notification,omitempty"`
 
 	// iOS
-	Expiration  int64    `json:"expiration,omitempty"`
+	Expiration  *int64   `json:"expiration,omitempty"`
 	ApnsID      string   `json:"apns_id,omitempty"`
 	CollapseID  string   `json:"collapse_id,omitempty"`
 	Topic       string   `json:"topic,omitempty"`
diff --git a/gorush/notification_apns.go b/gorush/notification_apns.go
index 79ba53a..dc4b289 100644
--- a/gorush/notification_apns.go
+++ b/gorush/notification_apns.go
@@ -175,8 +175,8 @@ func GetIOSNotification(req PushNotification) *apns2.Notification {
 		CollapseID: req.CollapseID,
 	}
 
-	if req.Expiration > 0 {
-		notification.Expiration = time.Unix(req.Expiration, 0)
+	if req.Expiration != nil {
+		notification.Expiration = time.Unix(*req.Expiration, 0)
 	}
 
 	if len(req.Priority) > 0 && req.Priority == "normal" {