diff --git a/modules/mod_search/mod_search.php b/modules/mod_search/mod_search.php
index 6ccad3ddcdaba..67541f70dcb74 100644
--- a/modules/mod_search/mod_search.php
+++ b/modules/mod_search/mod_search.php
@@ -41,7 +41,7 @@
 $maxlength       = $upper_limit;
 $text            = htmlspecialchars($params->get('text', JText::_('MOD_SEARCH_SEARCHBOX_TEXT')), ENT_COMPAT, 'UTF-8');
 $label           = htmlspecialchars($params->get('label', JText::_('MOD_SEARCH_LABEL_TEXT')), ENT_COMPAT, 'UTF-8');
-$moduleclass_sfx = htmlspecialchars($params->get('moduleclass_sfx'), ENT_COMPAT, 'UTF-8');
+$moduleclass_sfx = htmlspecialchars($params->get('moduleclass_sfx', ''), ENT_COMPAT, 'UTF-8');
 
 if ($imagebutton)
 {