diff --git a/gtk-3.0/gtk-dark.css b/gtk-3.0/gtk-dark.css
index 9dd5736..eed4b50 100755
--- a/gtk-3.0/gtk-dark.css
+++ b/gtk-3.0/gtk-dark.css
@@ -2665,8 +2665,8 @@ window.csd > .titlebar:not(headerbar) {
   border-color: transparent;
   box-shadow: none; }
 
-.titlebar:not(headerbar) > separator {
-  background: transparent; }
+.titlebar:not(headerbar) > separator, .titlebar:not(headerbar) > separator:backdrop {
+  background: #0c0e14; }
 
 /**************
  * GtkInfoBar *
diff --git a/gtk-3.0/gtk.css b/gtk-3.0/gtk.css
index 9dd5736..eed4b50 100755
--- a/gtk-3.0/gtk.css
+++ b/gtk-3.0/gtk.css
@@ -2665,8 +2665,8 @@ window.csd > .titlebar:not(headerbar) {
   border-color: transparent;
   box-shadow: none; }
 
-.titlebar:not(headerbar) > separator {
-  background: transparent; }
+.titlebar:not(headerbar) > separator, .titlebar:not(headerbar) > separator:backdrop {
+  background: #0c0e14; }
 
 /**************
  * GtkInfoBar *
diff --git a/gtk-3.0/widgets/_header-bars.scss b/gtk-3.0/widgets/_header-bars.scss
index f24399a..a727fe1 100644
--- a/gtk-3.0/widgets/_header-bars.scss
+++ b/gtk-3.0/widgets/_header-bars.scss
@@ -271,7 +271,9 @@ headerbar {
   }
 
   > separator {
-    background: transparent;
+    &, &:backdrop {
+      background: $headerbar_color;
+    }
   }
 
   @extend %titlebar;