diff --git a/composer-dist.json b/composer-dist.json
index 8d63f2f38..c58f08e11 100644
--- a/composer-dist.json
+++ b/composer-dist.json
@@ -13,6 +13,9 @@
     "config": {
         "platform": {
             "php": "8.2"
+        },
+        "allow-plugins": {
+            "wikimedia/composer-merge-plugin": true
         }
     },
     "require": {
@@ -46,11 +49,26 @@
         "seeddms/lucene": "dev-master",
         "seeddms/preview": "dev-master",
         "seeddms/sqlitefts": "dev-master",
-        "seeddms/http_webdav_server": "dev-master"
+        "seeddms/http_webdav_server": "dev-master",
+        "wikimedia/composer-merge-plugin": "dev-master"
     },
     "require-dev": {
         "composer/composer": "dev-main"
     },
+    "extra": {
+        "merge-plugin": {
+            "include": [
+                "composer.local.json"
+            ],
+            "recurse": false,
+            "replace": true,
+            "ignore-duplicates": true,
+            "merge-dev": true,
+            "merge-extra": false,
+            "merge-extra-deep": false,
+            "merge-scripts": true
+        }
+    },
     "repositories": [
         {
             "type": "path",
diff --git a/composer.json b/composer.json
index 75bac27ec..e39a55b09 100644
--- a/composer.json
+++ b/composer.json
@@ -52,7 +52,8 @@
         "seeddms/lucene": "dev-master",
         "seeddms/preview": "dev-master",
         "seeddms/sqlitefts": "dev-master",
-        "seeddms/http_webdav_server": "dev-master"
+        "seeddms/http_webdav_server": "dev-master",
+        "wikimedia/composer-merge-plugin": "dev-master"
     },
     "require-dev": {
         "composer/composer": "dev-main",
@@ -110,9 +111,9 @@
             "include": [
                 "composer.local.json"
             ],
-            "recurse": true,
+            "recurse": false,
             "replace": true,
-            "ignore-duplicates": false,
+            "ignore-duplicates": true,
             "merge-dev": true,
             "merge-extra": false,
             "merge-extra-deep": false,