diff --git a/core/includes/entity.inc b/core/includes/entity.inc
index 708706e..ac5b323 100644
--- a/core/includes/entity.inc
+++ b/core/includes/entity.inc
@@ -428,7 +428,7 @@ function entity_form_id(EntityInterface $entity, $operation = 'default') {
   $bundle = $entity->bundle();
   $form_id = $entity_type;
   if ($bundle != $entity_type) {
-    $form_id = $bundle . '_' . $form_id;
+    $form_id .= '_' . $bundle;
   }
   if ($operation != 'default') {
     $form_id = $form_id . '_' . $operation;