diff --git a/composer.json b/composer.json
old mode 100755
new mode 100644
index 9f0b0df..6b648b0
--- a/composer.json
+++ b/composer.json
@@ -8,7 +8,7 @@
         "psr/http-message": "^1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8.6"
+        "phpunit/phpunit": "^5.7.27"
     },
     "autoload": {
         "psr-4": {