diff --git a/src/Form/Field/Checkbox.php b/src/Form/Field/Checkbox.php
index 7b60227451..f6358761da 100644
--- a/src/Form/Field/Checkbox.php
+++ b/src/Form/Field/Checkbox.php
@@ -126,7 +126,7 @@ public function render()
             'checked'     => $this->checked,
             'inline'      => $this->inline,
             'canCheckAll' => $this->canCheckAll,
-            'groups'      => $this->groups
+            'groups'      => $this->groups,
         ]);
 
         if ($this->canCheckAll) {