diff --git a/libraries/cms/html/select.php b/libraries/cms/html/select.php
index 0eeddab57606d..b53adcf6a9743 100644
--- a/libraries/cms/html/select.php
+++ b/libraries/cms/html/select.php
@@ -219,7 +219,7 @@ public static function groupedlist($data, $name, $options = array())
 
 		$baseIndent = str_repeat($options['format.indent'], $options['format.depth']++);
 		$html = $baseIndent . '<select' . ($id !== '' ? ' id="' . $id . '"' : '')
-				. ' name="' . $name . '"' . $attribs . ' class="custom-select">' . $options['format.eol'];
+				. ' name="' . $name . '"' . $attribs . '>' . $options['format.eol'];
 		$groupIndent = str_repeat($options['format.indent'], $options['format.depth']++);
 
 		foreach ($data as $dataKey => $group)