diff --git a/core/themes/bartik/css/components/vertical-tabs.component.css b/core/themes/bartik/css/components/vertical-tabs.component.css
index a754952..4be47e0 100644
--- a/core/themes/bartik/css/components/vertical-tabs.component.css
+++ b/core/themes/bartik/css/components/vertical-tabs.component.css
@@ -5,5 +5,6 @@ ul.vertical-tabs-list {
 }
 [dir="rtl"] ul.vertical-tabs-list {
   margin: -1px -15em -1px 0;
+  /* This is required to win specificity over [dir="rtl"] .region-content ul */
   padding: 0;
 }