--- a/browser/themes/shared/customizableui/panelUI.inc.css
+++ b/browser/themes/shared/customizableui/panelUI.inc.css
@@ -1293,16 +1293,20 @@ photonpanelmultiview .subviewbutton[chec
 }
 
 photonpanelmultiview .panel-banner-item > .toolbarbutton-multiline-text {
   font: menu;
   padding: 0;
   padding-inline-start: 8px; /* See '.subviewbutton-iconic > .toolbarbutton-text' rule above. */
 }
 
+photonpanelmultiview .subviewbutton-iconic > .toolbarbutton-icon {
+  width: 16px;
+}
+
 photonpanelmultiview .subviewbutton {
   -moz-context-properties: fill;
   fill: currentColor;
 }
 
 photonpanelmultiview .subviewbutton[checked="true"] {
   background: none;
   list-style-image: url(chrome://browser/skin/check.svg);