diff --git a/src/gtk-3.20/scss/widgets/_toolbar.scss b/src/gtk-3.20/scss/widgets/_toolbar.scss
index 12f28c5..bd650a5 100644
--- a/src/gtk-3.20/scss/widgets/_toolbar.scss
+++ b/src/gtk-3.20/scss/widgets/_toolbar.scss
@@ -222,9 +222,11 @@
     // Fixed: https://github.com/numixproject/numix-gtk-theme/issues/585
     // workaround for ugly Ubuntu-related CSD patches
     .background:not(.csd):not(.ssd):not(.solid-csd) headerbar {
-        &, &:not(:last-child) {
-            border-radius: 0;
-            border-top-color: transparent;
+        &, &:backdrop {
+            &, &:not(:last-child) {
+                border-radius: 0;
+                border-top-color: transparent;
+            }
         }
     }
 }