diff --git a/browser/base/content/browser-verticaltabs.css b/browser/base/content/browser-verticaltabs.css
index 13e0ab6c..737a190f 100644
--- a/browser/base/content/browser-verticaltabs.css
+++ b/browser/base/content/browser-verticaltabs.css
@@ -13,7 +13,6 @@
   min-width: 150px !important;
   transition :min-width 150ms ease-out, max-width 150ms ease-out !important;
   overflow: hidden !important;
-  -moz-window-dragging: no-drag;
 }
 
 #TabsToolbar:-moz-lwtheme {