diff --git a/platform/elmapi/callback.go b/platform/elmapi/callback.go
index 10f70769..eb672a16 100644
--- a/platform/elmapi/callback.go
+++ b/platform/elmapi/callback.go
@@ -22,14 +22,14 @@ type ELMCallbackResponse struct {
 }
 
 type ELMCallbackMsg struct {
-	AppId     int    `json:"appId"`
-	RequestId string `json:"requestId"`
-	Type      int    `json:"type"`
-	Message   string `json:"message"`
-	ShopId    int    `json:"shopId"`
-	Timestamp int64  `json:"timestamp"`
-	UserId    int64  `json:"userId"`
-	Signature string `json:"signature"`
+	AppId     int    `json:"appId" structs:"appId"`
+	RequestId string `json:"requestId" structs:"requestId"`
+	Type      int    `json:"type" structs:"type"`
+	Message   string `json:"message" structs:"message"`
+	ShopId    int    `json:"shopId" structs:"shopId"`
+	Timestamp int64  `json:"timestamp" structs:"timestamp"`
+	UserId    int64  `json:"userId" structs:"userId"`
+	Signature string `json:"signature" structs:"signature"`
 }
 
 var (
@@ -48,8 +48,8 @@ func (e *ELMAPI) unmarshalData(data []byte, msg interface{}) (callbackResponse *
 
 func (e *ELMAPI) CheckRequestValidation(mapData map[string]interface{}) (callbackResponse *ELMCallbackResponse) {
 	sign := e.signParamsMap(mapData, "")
-	if sign != mapData[signKey].(string) {
-		e.sugarLogger.Infof("Signature is not ok, mine:%v, get:%v", sign, mapData[signKey].(string))
+	if remoteSign, ok := mapData[signKey].(string); ok && sign != remoteSign {
+		e.sugarLogger.Infof("Signature is not ok, mine:%v, get:%v", sign, remoteSign)
 		return &ELMCallbackResponse{Message: "signature is invalid"}
 	}
 	return nil