diff --git a/skin/classic/treestyletab/metal/base.css b/skin/classic/treestyletab/metal/base.css
index 357732e5..ef27c57d 100644
--- a/skin/classic/treestyletab/metal/base.css
+++ b/skin/classic/treestyletab/metal/base.css
@@ -95,12 +95,16 @@ tabbrowser[treestyletab-style="metal"][treestyletab-mode="vertical"]
 	background: #e4e4e4 !important;
 }
 tabbrowser[treestyletab-style="metal"][treestyletab-tabbar-position="left"]
-  .treestyletab-splitter {
-	border-right-width: 1px !important;
+  .treestyletab-splitter,
+.tabbrowser-strip[treestyletab-style="metal"][treestyletab-tabbar-position="left"][treestyletab-tabbar-fixed="true"],
+#TabsToolbar[treestyletab-style="metal"][treestyletab-tabbar-position="left"][treestyletab-tabbar-fixed="true"] {
+	border-right: 1px solid #666666 !important;
 }
 tabbrowser[treestyletab-style="metal"][treestyletab-tabbar-position="right"]
-  .treestyletab-splitter {
-	border-left-width: 1px !important;
+  .treestyletab-splitter,
+.tabbrowser-strip[treestyletab-style="metal"][treestyletab-tabbar-position="right"][treestyletab-tabbar-fixed="true"],
+#TabsToolbar[treestyletab-style="metal"][treestyletab-tabbar-position="right"][treestyletab-tabbar-fixed="true"] {
+	border-left: 1px solid #666666 !important;
 }
 
 
diff --git a/skin/classic/treestyletab/sidebar/sidebar.css b/skin/classic/treestyletab/sidebar/sidebar.css
index 942c92b9..a06744ed 100644
--- a/skin/classic/treestyletab/sidebar/sidebar.css
+++ b/skin/classic/treestyletab/sidebar/sidebar.css
@@ -44,6 +44,20 @@ tabbrowser[treestyletab-style="sidebar"][treestyletab-mode="vertical"] .treestyl
 tabbrowser[treestyletab-style="sidebar"][treestyletab-mode="vertical"] .treestyletab-splitter {
   background-color: #868686;
 }
+.tabbrowser-strip[treestyletab-style="sidebar"][treestyletab-tabbar-position="left"][treestyletab-tabbar-fixed="true"] {
+  border-right: 1px solid #404040;
+}
+#main-window:not([active="true"])
+.tabbrowser-strip[treestyletab-style="sidebar"][treestyletab-tabbar-position="left"][treestyletab-tabbar-fixed="true"] {
+  border-right-color: #868686;
+}
+.tabbrowser-strip[treestyletab-style="sidebar"][treestyletab-tabbar-position="right"][treestyletab-tabbar-fixed="true"] {
+  border-left: 1px solid #404040;
+}
+#main-window:not([active="true"])
+.tabbrowser-strip[treestyletab-style="sidebar"][treestyletab-tabbar-position="right"][treestyletab-tabbar-fixed="true"] {
+  border-left-color: #868686;
+}
 
 /* Style tabs themselves.  Get rid of most of the initial XUL styling */
 .tabbrowser-tabs[treestyletab-style="sidebar"][treestyletab-mode="vertical"] .tabbrowser-tab {