diff --git a/tests/composer.json b/tests/composer.json
index e43fb45a..3d8757ec 100644
--- a/tests/composer.json
+++ b/tests/composer.json
@@ -24,9 +24,8 @@
     "issues": "http://code.google.com/p/smarty-php/issues/list",
     "forum": "http://www.smarty.net/forums/"
   },
-  "minimum-stability" : "stable",
   "require": {
-    "phpunit/phpunit": "*",
+    "phpunit/phpunit": "~",
     "php": ">=5.2"
   },
   "autoload": {