diff --git a/htdocs/theme/md/style.css.php b/htdocs/theme/md/style.css.php
index 16dce1c5206..c079ff3134d 100644
--- a/htdocs/theme/md/style.css.php
+++ b/htdocs/theme/md/style.css.php
@@ -1903,6 +1903,7 @@ div.tabsAction > a {
 
 div.popuptabset {
 	padding: 6px;
+	background: #fff;
 	border: 1px solid #888;
 }
 div.popuptab {