diff --git a/lib/wx_pay/service.rb b/lib/wx_pay/service.rb
index d60973b..69e491c 100644
--- a/lib/wx_pay/service.rb
+++ b/lib/wx_pay/service.rb
@@ -27,9 +27,10 @@ module WxPay
       ), quirks_mode: true)
     end
 
-    def self.get_sandbox_signkey(mch_id = WxPay.mch_id)
+    def self.get_sandbox_signkey(mch_id = WxPay.mch_id, options = {})
       params = {
         mch_id: mch_id,
+        key: options.delete(:key) || WxPay.key,
         nonce_str: SecureRandom.uuid.tr('-', '')
       }
       r = WxPay::Result.new(Hash.from_xml(invoke_remote("/pay/getsignkey", xmlify_payload(params))))
diff --git a/lib/wx_pay/sign.rb b/lib/wx_pay/sign.rb
index e4c1eeb..3464e35 100644
--- a/lib/wx_pay/sign.rb
+++ b/lib/wx_pay/sign.rb
@@ -25,11 +25,9 @@ module WxPay
     end
 
     def self.verify?(params, options = {})
+      return true if WxPay.sandbox_mode?
       params = params.dup
       params = params.merge(options)
-      if WxPay.sandbox_mode? && !params[:key]
-        params[:key] = WxPay.sandbox_key
-      end
       sign = params.delete('sign') || params.delete(:sign)
       generate(params) == sign
     end
--
libgit2 0.21.0