diff --git a/workbench_moderation_buttons.module b/workbench_moderation_buttons.module
index a2fda5c..c7e4c06 100644
--- a/workbench_moderation_buttons.module
+++ b/workbench_moderation_buttons.module
@@ -41,7 +41,7 @@ function workbench_moderation_buttons_form_node_form_alter(&$form, $state, $form
         '#type' => 'submit',
         '#value' => $label,
         // 10's the weight for preview button.
-        '#weight' => 11  $key,
+        '#weight' => 11 + $key,
       );
       $label_machine_names[$label] = $machine_name;
      }