diff --git a/composer.json b/composer.json
index 964f496..1ba311c 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,7 @@
     "php": ">=5.4"
   },
   "require-dev": {
-    "phpunit/phpunit": "4.7.*"
+    "phpunit/phpunit": "4.7.* || 4.8.*"
   },
   "autoload": {
     "files": [ "Resources/functions/recursiveImplode.php" ],