diff --git a/README.md b/README.md
index 06f1d24..25707b6 100644
--- a/README.md
+++ b/README.md
@@ -180,6 +180,10 @@ Optional features can be enabled by creating new `boolean` preferences in `about
 
 	Use normal width tabs as default Firefox.
 
+- **Bookmarks toolbar under tabs** `gnomeTheme.bookmarksToolbarUnderTabs`
+
+	Move Bookmarks toolbar under tabs.
+
 - **Active tab contrast** `gnomeTheme.activeTabContrast`
 
 	Add more contrast to the active tab.
diff --git a/theme/parts/toolbox.css b/theme/parts/toolbox.css
index dc45519..849e338 100644
--- a/theme/parts/toolbox.css
+++ b/theme/parts/toolbox.css
@@ -58,10 +58,10 @@ findbar:-moz-window-inactive description,
 #navigator-toolbox #nav-bar, findbar {
 	-moz-box-ordinal-group: 0;
 }
-#navigator-toolbox #titlebar {
+#navigator-toolbox #PersonalToolbar {
 	-moz-box-ordinal-group: 1;
 }
-#navigator-toolbox #PersonalToolbar {
+#navigator-toolbox #titlebar {
 	-moz-box-ordinal-group: 2;
 }
 #navigator-toolbox toolbar {
@@ -126,3 +126,12 @@ findbar:-moz-window-inactive description,
 	}
 }
 
+/* OPTIONAL: Move bookmarks bar under tabs */
+@supports -moz-bool-pref("gnomeTheme.bookmarksToolbarUnderTabs") {
+	#navigator-toolbox #titlebar {
+		-moz-box-ordinal-group: 1 !important;
+	}
+	#navigator-toolbox #PersonalToolbar {
+		-moz-box-ordinal-group: 2 !important;
+	}
+}