diff --git a/src/browser/base/content/zen-styles/zen-tabs/vertical-tabs.css b/src/browser/base/content/zen-styles/zen-tabs/vertical-tabs.css
index 993def647..9dd3d48ad 100644
--- a/src/browser/base/content/zen-styles/zen-tabs/vertical-tabs.css
+++ b/src/browser/base/content/zen-styles/zen-tabs/vertical-tabs.css
@@ -31,6 +31,7 @@
   
   #TabsToolbar-customization-target {
     flex-direction: column;
+    max-width: 100%;
   }
   
   :root[customizing] .customization-target:not(#widget-overflow-fixed-list) {