diff --git a/composer.json b/composer.json
index 8a8a52e..097d9e4 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,7 @@
         "league/oauth2-client": "^1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.0",
+        "phpunit/phpunit": "^4.8 || ^5.0",
         "mockery/mockery": "~0.9"
     },
     "autoload": {