diff --git a/composer.json b/composer.json
index 76e1e74..42c48d2 100644
--- a/composer.json
+++ b/composer.json
@@ -53,7 +53,8 @@
             "drupal/core-project-message": true,
             "phpstan/extension-installer": true,
             "dealerdirect/phpcodesniffer-composer-installer": true,
-            "php-http/discovery": true
+            "php-http/discovery": true,
+            "wikimedia/composer-merge-plugin": true
         }
     },
     "extra": {
@@ -111,6 +112,11 @@
             "web/themes/custom/{$name}": [
                 "type:drupal-custom-theme"
             ]
+        },
+        "merge-plugin": {
+            "include": [
+                "web/modules/contrib/webform/composer.libraries.json"
+            ]
         }
     }
 }