diff --git a/browser/themes/osx/browser.css b/browser/themes/osx/browser.css
index fc3ad9714df..3d7f8097f75 100644
--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -4152,7 +4152,7 @@ window > chatbox {
 }
 
 #main-window[tabsintitlebar][customize-entered] #TabsToolbar {
-  margin-top: 9px;
+  margin-top: 8px;
 }
 
 #main-window[customize-entered] #TabsToolbar {