diff --git a/browser/themes/shared/customizableui/panelUIOverlay.inc.css b/browser/themes/shared/customizableui/panelUIOverlay.inc.css
index c3e97e88b9e5..ce1d8e3ab8ce 100644
--- a/browser/themes/shared/customizableui/panelUIOverlay.inc.css
+++ b/browser/themes/shared/customizableui/panelUIOverlay.inc.css
@@ -201,8 +201,8 @@ toolbaritem[cui-areatype="menu-panel"][sdkstylewidget="true"]:not(.panel-wide-it
 }
 
 /* Help SDK buttons fit in. */
-toolbarpaletteitem[place="palette"] > #personal-bookmarks > #bookmarks-toolbar-placeholder,
-#personal-bookmarks[cui-areatype="menu-panel"] > #bookmarks-toolbar-placeholder {
+toolbarpaletteitem[place="palette"] > toolbarbutton[sdk-button="true"] > .toolbarbutton-icon,
+toolbarbutton[sdk-button="true"][cui-areatype="menu-panel"] > .toolbarbutton-icon {
   height: 32px;
   width: 32px;
 }