diff --git a/composer.json b/composer.json
index 453cf3d..ae1ba42 100644
--- a/composer.json
+++ b/composer.json
@@ -18,7 +18,7 @@
     },
     "require": {
         "php": ">=5.5",
-        "phpunit/phpunit": "^4.0.0",
+        "phpunit/phpunit": "^4.0|^5.0",
         "php-mock/php-mock-integration": "^0.4"
     },
     "require-dev": {