diff --git a/src/BaseHtml.php b/src/BaseHtml.php
index c919fb5..1baf6df 100644
--- a/src/BaseHtml.php
+++ b/src/BaseHtml.php
@@ -27,6 +27,13 @@ abstract class BaseHtml extends \yii\helpers\Html
* @see getId()
*/
public static $autoIdPrefix = 'i';
+ /**
+ * @var bool whether to removes duplicate class names in tag attribute `class` (fix strange yii2 behavior since 2.0.44)
+ * @see mergeCssClasses()
+ * @see renderTagAttributes()
+ * @since 2.0.3
+ */
+ public static $normalizeClassAttribute = true;
/**