diff --git a/src/Symfony/Component/Process/ExecutableFinder.php b/src/Symfony/Component/Process/ExecutableFinder.php
index 824457ce2a..d8e689622a 100644
--- a/src/Symfony/Component/Process/ExecutableFinder.php
+++ b/src/Symfony/Component/Process/ExecutableFinder.php
@@ -75,7 +75,7 @@ class ExecutableFinder
         $suffixes = array('');
         if ('\\' === DIRECTORY_SEPARATOR) {
             $pathExt = getenv('PATHEXT');
-            $suffixes = $pathExt ? explode(PATH_SEPARATOR, $pathExt) : $this->suffixes;
+            $suffixes = array_merge($suffixes, $pathExt ? explode(PATH_SEPARATOR, $pathExt) : $this->suffixes);
         }
         foreach ($suffixes as $suffix) {
             foreach ($dirs as $dir) {