diff --git a/composer.json b/composer.json
index b3f7f48..defae6c 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
         }
     ],
     "require": {
-        "php": ">=5.4",
+        "php": "^5.4|^7.0",
         "beberlei/assert": "~2.0",
         "psr/log": "~1.0"
     },