diff --git a/composer.json b/composer.json
index 4dfb747..a0a86a9 100644
--- a/composer.json
+++ b/composer.json
@@ -27,7 +27,7 @@
 		"sort-packages": true
     },
     "require-dev":       {
-        "phpunit/phpunit": "^5.7 || ^6.5"
+        "phpunit/phpunit": "^5.7"
     },
     "autoload":          {
         "psr-4": {