diff --git themes/bartik/css/style.css themes/bartik/css/style.css
index d37754c..570e151 100644
--- themes/bartik/css/style.css
+++ themes/bartik/css/style.css
@@ -1434,6 +1434,9 @@ div.password-suggestions {
 div.vertical-tabs .vertical-tabs-panes fieldset.vertical-tabs-pane {
   padding: 1em;
 }
+fieldset .form-item-timezone select {
+  width: 100%;
+}
 #forum tr td.forum {
   padding-left: 35px;
 }