diff --git a/composer.json b/composer.json
index a9d4aafc3..973e0753f 100644
--- a/composer.json
+++ b/composer.json
@@ -44,7 +44,8 @@
     "preferred-install": {
       "*": "dist"
     },
-    "sort-packages": true
+    "sort-packages": true,
+    "classmap-authoritative": true
   },
   "autoload": {
     "classmap": [