diff --git a/composer.json b/composer.json
index ba4f8e6..fc35f27 100644
--- a/composer.json
+++ b/composer.json
@@ -11,11 +11,11 @@
         }
     ],
     "require": {
-        "php": ">=5.3.0",
+        "php": "^5.5.9|>=7.0.8",
         "naucon/utility": "~1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "4.8.*"
+        "phpunit/phpunit": "~4.8 || ^5.6"
     },
     "autoload": {
         "psr-4": {"Naucon\\File\\": "src/"}