diff --git a/themes/base/ui.tabs.css b/themes/base/ui.tabs.css
index ebaca3225..48f7661b7 100644
--- a/themes/base/ui.tabs.css
+++ b/themes/base/ui.tabs.css
@@ -4,8 +4,8 @@
 .ui-tabs .ui-tabs-nav { padding: .2em .2em 0 .2em;  position: relative; }
 .ui-tabs .ui-tabs-nav li { float: left; border-bottom-width: 0 !important; margin: 0 .2em -1px 0; padding: 0; list-style: none; }
 .ui-tabs .ui-tabs-nav li a { float: left; display:block; text-decoration: none; padding: .5em 1em; }
-.ui-tabs .ui-tabs-nav li.ui-tabs-selected {  padding-bottom: .1em; border-bottom: 0; }
+.ui-tabs .ui-tabs-nav li.ui-tabs-selected {  padding-bottom: .1em; border-bottom-width: 0; }
 .ui-tabs .ui-tabs-nav li.ui-tabs-selected a { cursor: text; }
 .ui-tabs .ui-tabs-nav li a, .ui-tabs.ui-tabs-collapsible .ui-tabs-nav li.ui-tabs-selected a { cursor: pointer; } /* first selector in group seems obsolete, but required to overcome bug in Opera applying cursor: text overall if defined elsewhere... */
-.ui-tabs .ui-tabs-panel { padding: 1em 1.4em;  display: block; border: 0; background: none; }
+.ui-tabs .ui-tabs-panel { padding: 1em 1.4em;  display: block; border-width: 0; background: none; }
 .ui-tabs .ui-tabs-hide { display: none !important; }