diff --git a/.github/workflows/duplicated_code.yaml b/.github/workflows/duplicated_code.yaml
new file mode 100644
index 00000000..2f87364f
--- /dev/null
+++ b/.github/workflows/duplicated_code.yaml
@@ -0,0 +1,29 @@
+name: Duplicated Code
+
+on:
+    pull_request: null
+    push:
+        branches:
+            - main
+
+env:
+    COMPOSER_ROOT_VERSION: "dev-main"
+
+jobs:
+    duplicated_code:
+        runs-on: ubuntu-latest
+        timeout-minutes: 5
+
+        steps:
+            -   uses: actions/checkout@v4
+
+            -
+                uses: shivammathur/setup-php@v2
+                with:
+                    php-version: 8.4
+                    coverage: none
+
+            -   uses: "ramsey/composer-install@v2"
+
+            # fails when a large copy-pasted block (>= 150 tokens) is added
+            -   run: composer duplicated-code
diff --git a/composer.json b/composer.json
index 9b42ed35..49b24972 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
         "phpunit/phpunit": "^13.2",
         "rector/jack": "^1.0",
         "rector/rector-src": "dev-main",
-        "rector/swiss-knife": "^2.4",
+        "rector/swiss-knife": "^2.6",
         "symplify/easy-coding-standard": "^13.2",
         "symplify/phpstan-extensions": "^12.0",
         "symplify/phpstan-rules": "^14.13.1",
@@ -46,6 +46,7 @@
             "phpunit"
         ],
         "phpstan": "vendor/bin/phpstan analyse --ansi",
+        "duplicated-code": "vendor/bin/swiss-knife duplicated-code src rules --min-tokens 150 --min-lines 5",
         "check-cs": "vendor/bin/ecs check --ansi",
         "class-leak": "vendor/bin/class-leak check config src rules --skip-suffix \"Rector\"",
         "fix-cs": "vendor/bin/ecs check --fix --ansi",