diff --git a/composer.json b/composer.json
index 072574c..c46e83d 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
         "php" : "~5.5|~7.0"
     },
     "require-dev": {
-        "phpunit/phpunit" : "4.*",
+        "phpunit/phpunit" : "~4.0||~5.0",
         "scrutinizer/ocular": "~1.1",
         "squizlabs/php_codesniffer": "~2.3"
     },