diff --git a/application/modules/user/mappers/ProfileFields.php b/application/modules/user/mappers/ProfileFields.php
index 1b14babb4..5b134ab42 100644
--- a/application/modules/user/mappers/ProfileFields.php
+++ b/application/modules/user/mappers/ProfileFields.php
@@ -60,10 +60,10 @@ public function getProfileFieldById(int $id): ?ProfileFieldModel
     /**
      * Returns a ProfileField model found by the key.
      *
-     * @param int $key
+     * @param string $key
      * @return null|ProfileFieldModel
      */
-    public function getProfileFieldIdByKey(int $key): ?ProfileFieldModel
+    public function getProfileFieldIdByKey(string $key): ?ProfileFieldModel
     {
         $profileFieldRow = $this->db()->select('*')
             ->from('profile_fields')