diff --git a/composer.json b/composer.json
index d38ab83..0d9194c 100644
--- a/composer.json
+++ b/composer.json
@@ -56,6 +56,7 @@
     },
     "conflict": {
         "nyholm/psr7": "<1.0",
+        "sebastian/comparator": ">=5.0",
         "zendframework/zend-diactoros": "*"
     },
     "prefer-stable": true,