diff --git a/src/Element/RangeSlider.php b/src/Element/RangeSlider.php
index d9e22e1..ee72db8 100644
--- a/src/Element/RangeSlider.php
+++ b/src/Element/RangeSlider.php
@@ -41,6 +41,7 @@ class RangeSlider extends Range {
     return [
       '#process' => [
         [get_class($this), 'processRangeSlider'],
+        [get_class($this), 'processAjaxForm'],
       ],
       '#data-orientation' => 'horizontal',
       '#output' => FALSE,