diff --git a/src/Common/UiElement.php b/src/Common/UiElement.php
index 982033a..f130a4c 100644
--- a/src/Common/UiElement.php
+++ b/src/Common/UiElement.php
@@ -292,7 +292,7 @@ class UiElement implements \ArrayAccess, \Iterator, \JsonSerializable {
 
                 default:
                     if ( is_numeric($key) ) {
-                        $this->attributes[] = $value;
+                        $this->attributes[$key] = $value;
                     }
                     elseif ( is_array($this->attributes[$key] ?? false) ) {
                         $this->attributes[$key] = array_replace($value, $this->attributes[$key]);