diff --git a/core/themes/bartik/css/layout.css b/core/themes/bartik/css/layout.css
index 7b53f796ea3..1456058e96d 100644
--- a/core/themes/bartik/css/layout.css
+++ b/core/themes/bartik/css/layout.css
@@ -100,14 +100,14 @@ body,
   [dir="rtl"] #sidebar-second {
     margin-right: 50%;
   }
-  .one-sidebar #sidebar-first,
-  .one-sidebar #sidebar-second {
+  .layout-one-sidebar #sidebar-first,
+  .layout-one-sidebar #sidebar-second {
     width: 100%;
   }
-  .one-sidebar #sidebar-second {
+  .layout-one-sidebar #sidebar-second {
     margin-left: 0; /* LTR */
   }
-  [dir="rtl"] .one-sidebar #sidebar-second {
+  [dir="rtl"] .layout-one-sidebar #sidebar-second {
     margin-right: 0;
   }
   .region-triptych-first,