diff --git a/src/Hprose/Service.php b/src/Hprose/Service.php
index e17ba498..f0e70bf9 100644
--- a/src/Hprose/Service.php
+++ b/src/Hprose/Service.php
@@ -14,7 +14,7 @@
  *                                                        *
  * hprose service class for php 5.3+                      *
  *                                                        *
- * LastModified: Nov 6, 2016                              *
+ * LastModified: Feb 16, 2017                             *
  * Author: Ma Bingyao <andot@hprose.com>                  *
  *                                                        *
 \**********************************************************/
@@ -400,6 +400,7 @@ private function doInvoke(BytesIO $stream, stdClass $context) {
             foreach ($context as $key => $value) {
                 $cc->$key = $value;
             }
+            $call = false;
             if (isset($this->calls[$alias])) {
                 $call = $this->calls[$alias];
             }