diff --git a/src/Form/UiForm.php b/src/Form/UiForm.php
index c8f5b45..c513943 100644
--- a/src/Form/UiForm.php
+++ b/src/Form/UiForm.php
@@ -31,6 +31,7 @@ class UiForm extends UiElement implements Extension {
         $constructor = [];
 
         switch($token) {
+            case 'ui.endform': # bw compat
             case 'ui:endform':
                 return "</form>";
         }