diff --git a/library/Zend/Test/PHPUnit/ControllerTestCase.php b/library/Zend/Test/PHPUnit/ControllerTestCase.php
index 1b8827d8d0..bb54d20184 100644
--- a/library/Zend/Test/PHPUnit/ControllerTestCase.php
+++ b/library/Zend/Test/PHPUnit/ControllerTestCase.php
@@ -1190,7 +1190,7 @@ public function urlizeOptions($urlOptions, $actionControllerModuleOnly = true)
     protected function _incrementAssertionCount()
     {
         $stack = debug_backtrace();
-        foreach (debug_backtrace() as $step) {
+        foreach ($stack as $step) {
             if (isset($step['object'])
                 && $step['object'] instanceof PHPUnit_Framework_TestCase
             ) {