diff --git a/composer.json b/composer.json
index ed28ef5..301ae87 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,7 @@
     "WeChatDeveloper"
   ],
   "require": {
-    "php": ">=5.4",
+    "php": ">=5.5",
     "ext-xml": "*",
     "ext-json": "*",
     "ext-curl": "*",