diff --git a/composer.json b/composer.json
index 2fd50f3..0a0d875 100644
--- a/composer.json
+++ b/composer.json
@@ -9,7 +9,7 @@
       }
     },
     "require": {
-      "php": ">=5.3.9",
+      "php": ">=5.6.0",
       "kint-php/kint": "^3.3",
       "symfony/yaml": "^2.8",
       "paragonie/random_compat": "^2",