diff --git a/css/leptonChrome.css b/css/leptonChrome.css
index 1162de4..85ba832 100644
--- a/css/leptonChrome.css
+++ b/css/leptonChrome.css
@@ -49,6 +49,12 @@
   #widget-overflow-mainView #zoom-in-button > .toolbarbutton-icon {
     padding-inline-start: 0px !important;
   }
+  /*= Subview button, Menu's right padding #597 ================================*/
+  .subviewbutton.toolbaritem-combined-buttons:not([shortcut]),
+  .subviewbutton.subviewbutton-nav:not([shortcut]),
+  menu.subviewbutton {
+    padding-inline-end: 0 !important;
+  }
   /*= Icon Fill Color ==========================================================*/
   :root:-moz-lwtheme {
     /* Auto create --lwt-toolbarbutton-icon-fill-attention, fix for nightly default theme
diff --git a/src/compatibility/_theme.scss b/src/compatibility/_theme.scss
index d46bf5c..331a8a2 100644
--- a/src/compatibility/_theme.scss
+++ b/src/compatibility/_theme.scss
@@ -24,6 +24,13 @@
   }
 }
 
+/*= Subview button, Menu's right padding #597 ================================*/
+.subviewbutton.toolbaritem-combined-buttons:not([shortcut]),
+.subviewbutton.subviewbutton-nav:not([shortcut]),
+menu.subviewbutton {
+  padding-inline-end: 0 !important;
+}
+
 /*= Icon Fill Color ==========================================================*/
 :root:-moz-lwtheme {
   /* Auto create --lwt-toolbarbutton-icon-fill-attention, fix for nightly default theme