diff --git a/composer.json b/composer.json
index e9490b1..2ab8a93 100644
--- a/composer.json
+++ b/composer.json
@@ -11,7 +11,7 @@
     "php": ">=5.4.0",
     "illuminate/support": "*",
     "vlucas/phpdotenv": "~1.0",
-    "symfony/process": "*",
+    "symfony/process": "~2.1",
     "illuminate/contracts": "*",
     "illuminate/console": "*",
     "illuminate/filesystem": "*"