diff --git a/.github/workflows/clean-vendor.yml b/.github/workflows/clean-vendor.yml
new file mode 100644
index 0000000..7e61e23
--- /dev/null
+++ b/.github/workflows/clean-vendor.yml
@@ -0,0 +1,26 @@
+name: Clean Vendor Check
+
+on:
+  push:
+    branches:
+      - stable/*
+
+jobs:
+  check-vendor:
+    name: Clean Vendor Check
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code base
+        uses: actions/checkout@v3
+
+      - name: Check If Vendor Is Clean
+        run: |
+          files=`find vendor -maxdepth 1 -type d -not -name "ipl" -not -name "fortawesome" -not -name "composer" -not -name "vendor"`
+          if [ -z "$files" ]; then
+            echo "No unknown vendor files found";
+            exit 0;
+          else
+            echo "Found unknown vendor files: $files";
+            exit 1;
+          fi
diff --git a/bin/make-release.sh b/bin/make-release.sh
index 0cc9a6c..9395242 100755
--- a/bin/make-release.sh
+++ b/bin/make-release.sh
@@ -53,6 +53,12 @@ rm -rf vendor
 git checkout vendor
 composer validate --no-check-all --strict || fail "Composer validate failed"
 
+UNKNOWN_VENDOR_FILES=$(find vendor -maxdepth 1 -type d -not -name "ipl" -not -name "fortawesome" -not -name "composer" -not -name "vendor")
+if [ -n "$UNKNOWN_VENDOR_FILES" ]; then
+  echo "Unknown vendor files found! DO NOT TAG!"
+  exit 1
+fi
+
 if [ -z "$NO_OPT" ]; then
   git tag -a v$VERSION -m "Version v$VERSION"
   echo "Finished, tagged v$VERSION"
diff --git a/composer.json b/composer.json
index 8cfce65..10b1e07 100644
--- a/composer.json
+++ b/composer.json
@@ -10,8 +10,15 @@
             "php": "7.2.9"
         }
     },
+    "repositories": [
+        {
+            "type": "path",
+            "url": "./replacer"
+        }
+    ],
     "require": {
         "php": ">=7.2",
+        "repl/acer": "@dev",
         "ipl/html": "^0.8.0",
         "ipl/i18n": "^0.2.0",
         "ipl/orm": "^0.6.0",
@@ -21,8 +28,6 @@
         "ipl/validator": "^0.5.0",
         "ipl/web": "^0.9.0"
     },
-    "require-dev": {
-    },
     "autoload": {
         "psr-0": { "AssetLoader": "" }
     },
diff --git a/replacer/composer.json b/replacer/composer.json
new file mode 100644
index 0000000..53f9cdf
--- /dev/null
+++ b/replacer/composer.json
@@ -0,0 +1,18 @@
+{
+  "name": "repl/acer",
+  "type": "metapackage",
+  "description": "Replaces third party packages as they are included in icinga-php-thirdparty",
+  "license": "MIT",
+  "replace": {
+    "psr/http-message": "*",
+    "guzzlehttp/psr7": "*",
+    "dragonmantank/cron-expression": "*",
+    "psr/log": "*",
+    "ramsey/uuid": "*",
+    "react/event-loop": "*",
+    "react/promise": "*",
+    "simshaun/recurr": "*",
+    "evenement/evenement": "*",
+    "wikimedia/less.php": "*"
+  }
+}