diff --git a/src/PreferencesWindow.vala b/src/PreferencesWindow.vala
index 5b18c93..ed0c74e 100644
--- a/src/PreferencesWindow.vala
+++ b/src/PreferencesWindow.vala
@@ -153,6 +153,7 @@ public class Workspaces.PreferencesWindow : Gtk.ApplicationWindow {
         var sidebar = new Gtk.Box (Gtk.Orientation.VERTICAL, 0);
         sidebar.get_style_context ().add_class ("pane");
         sidebar.pack_start (source_list, true, true, 0);
+        sidebar.add (new Gtk.Separator (Gtk.Orientation.HORIZONTAL));
         sidebar.pack_end (action_box, false, false, 0);
         /* End Sidebar */
 
diff --git a/src/QuickLaunchWindow.vala b/src/QuickLaunchWindow.vala
index 14ee831..0208fe3 100644
--- a/src/QuickLaunchWindow.vala
+++ b/src/QuickLaunchWindow.vala
@@ -127,6 +127,7 @@ public class Workspaces.QuickLaunchWindow : Gtk.Window {
         action_box.pack_start (add_revealer, false, false, 0);
         var main_box = new Gtk.Box (Gtk.Orientation.VERTICAL, 0);
         main_box.add (stack);
+        main_box.add (new Gtk.Separator (Gtk.Orientation.HORIZONTAL));
         main_box.add (action_box);
 
         add (main_box);