diff --git a/composer.json b/composer.json
index b45b26e..076585a 100644
--- a/composer.json
+++ b/composer.json
@@ -24,7 +24,7 @@
   "prefer-stable": true,
   "require": {
     "php": "^7.0",
-    "juliangut/mapping": "~0.3",
+    "juliangut/mapping": "~0.4",
     "psr/http-server-middleware": "^1.0",
     "slim/slim": "^3.8"
   },