diff --git a/.scrutinizer.yml b/.scrutinizer.yml
index 02bb0d0f4a..ac754cc957 100644
--- a/.scrutinizer.yml
+++ b/.scrutinizer.yml
@@ -39,6 +39,7 @@ checks:
         avoid_fixme_comments: true
         avoid_multiple_statements_on_same_line: true
         align_assignments: true
+        duplication: false
     javascript: true
 
 coding_style:
diff --git a/app/Http/Controllers/PreferencesController.php b/app/Http/Controllers/PreferencesController.php
index 93efecf2a8..f4bd94c4b5 100644
--- a/app/Http/Controllers/PreferencesController.php
+++ b/app/Http/Controllers/PreferencesController.php
@@ -113,6 +113,7 @@ class PreferencesController extends Controller
      * @param TokenFormRequest $request
      *
      * @return \Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter) // it's unused but the class does some validation.
      */
     public function postCode(TokenFormRequest $request)
     {