diff --git a/app/Models/CustomField.php b/app/Models/CustomField.php
index 7d5f1320c0..e0b06318bb 100644
--- a/app/Models/CustomField.php
+++ b/app/Models/CustomField.php
@@ -50,7 +50,7 @@ class CustomField extends Model
      */
     protected $rules = [
         'name' => 'required|unique:custom_fields',
-        'element' => 'required','in:text,listbox,textarea,checkbox,radio',
+        'element' => 'required|in:text,listbox,textarea,checkbox,radio',
         'field_encrypted' => 'nullable|boolean',
     ];