diff --git a/composer.json b/composer.json
index 0469f9f..03d0020 100644
--- a/composer.json
+++ b/composer.json
@@ -25,7 +25,7 @@
     },
 	"require-dev": {
 		"squizlabs/php_codesniffer": "*",
-		"phpunit/phpunit": "*",
+		"phpunit/phpunit": "3.7.*@stable",
 		"mockery/mockery": "*"
 	},
     "autoload": {