diff --git a/browser/themes/linux/browser.css b/browser/themes/linux/browser.css
index 74c69c28a9d5..01d6e317187d 100644
--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -107,15 +107,11 @@
 }
 
 #nav-bar {
-  box-shadow: 0 1px 0 @toolbarHighlight@ inset;
+  box-shadow: 0 1px 0 @navbarInsetHighlight@ inset;
   padding-top: 2px;
   padding-bottom: 2px;
 }
 
-#nav-bar:-moz-lwtheme {
-  box-shadow: 0 1px 0 @toolbarHighlightLWT@ inset;
-}
-
 #nav-bar-overflow-button {
   -moz-image-region: rect(-5px, 12px, 11px, -4px);
 }
diff --git a/browser/themes/linux/linuxShared.inc b/browser/themes/linux/linuxShared.inc
index 96a92b4b9645..a968512c14c7 100644
--- a/browser/themes/linux/linuxShared.inc
+++ b/browser/themes/linux/linuxShared.inc
@@ -6,6 +6,8 @@
 
 %define toolbarHighlight hsla(0,0%,100%,.05)
 %define toolbarHighlightLWT rgba(255,255,255,.4)
+/* navbarInsetHighlight is tightly coupled to the toolbarHighlight constant. */
+%define navbarInsetHighlight hsla(0,0%,100%,.4)
 %define fgTabTexture linear-gradient(transparent 2px, @toolbarHighlight@ 2px, @toolbarHighlight@)
 %define fgTabTextureLWT linear-gradient(transparent 2px, @toolbarHighlightLWT@ 2px, @toolbarHighlightLWT@)
 %define fgTabBackgroundColor -moz-dialog