diff --git a/composer.json b/composer.json
index fab20726..4339eaad 100644
--- a/composer.json
+++ b/composer.json
@@ -12,8 +12,8 @@
         }
     ],
     "require": {
-        "php": "^5.5.9 || ^7.0",
-        "psr/log": "^1.0.1"        
+        "php": "^5.4 || ^7.0",
+        "psr/log": "^1.0.1"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.8.35 || ^5.7",