diff --git a/PHPUnit/Util/Metrics/Function.php b/PHPUnit/Util/Metrics/Function.php
index 6d2dd780c38..8dc37a06257 100644
--- a/PHPUnit/Util/Metrics/Function.php
+++ b/PHPUnit/Util/Metrics/Function.php
@@ -97,7 +97,7 @@ protected function __construct($scope, $function, &$codeCoverage = array())
           $scope, $function->getName()
         );
 
-        if (!$source !== FALSE) {
+        if ($source !== FALSE) {
             $this->tokens     = token_get_all('<?php' . $source . '?>');
             $this->parameters = $function->getNumberOfParameters();