diff --git a/README.md b/README.md
index 31cc1ba..6ff8a2d 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ Run ```php composer.phar require denpa/php-bitapi``` in your project directory o
 and run ```php composer.phar update```.
 
 ## Requirements
-PHP 5.4 or higher
+PHP 5.6 or higher
 
 ## Usage
 Create new object
diff --git a/composer.json b/composer.json
index 2f9243e..e974fd3 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
         }
 	],
 	"require": {
-		"php": ">=5.4.0",
+		"php": ">=5.6.0",
         "guzzlehttp/guzzle": "^6.2"
     },
     "require-dev": {