diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index f7214f716d..fa19fbcb62 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -2092,6 +2092,7 @@ treeview.view {
 }
 
 
+
 /*********
  * Menus *
  *********/
@@ -2107,9 +2108,14 @@ menubar,
     min-height: 16px;
     padding: 4px 8px;
 
+    // remove padding and rounding from menubar submenus
     menu {
-    	border-radius: 0 0 $menu_radius $menu_radius;
-      	menu { border-radius: $menu_radius; }
+      border-radius: 0;
+      padding:0;
+      menu {
+        border-radius: 0;
+        padding:0;
+      }
     }
 
     &:hover { //Seems like it :hover even with keyboard focus
@@ -2122,6 +2128,9 @@ menubar,
       box-shadow: none;
     }
   }
+
+  // remove padding and rounding from menubar submenu decoration
+  .csd.popup decoration {border-radius:0;}
 }
 
 // Needed to make the border-radius of menus work
diff --git a/gtk/theme/Adwaita/gtk-contained-dark.css b/gtk/theme/Adwaita/gtk-contained-dark.css
index 252e85d97a..caf042b2ee 100644
--- a/gtk/theme/Adwaita/gtk-contained-dark.css
+++ b/gtk/theme/Adwaita/gtk-contained-dark.css
@@ -801,14 +801,16 @@ menubar:backdrop, .menubar:backdrop { background-color: #353535; }
 
 menubar > menuitem, .menubar > menuitem { min-height: 16px; padding: 4px 8px; }
 
-menubar > menuitem menu, .menubar > menuitem menu { border-radius: 0 0 5px 5px; }
+menubar > menuitem menu, .menubar > menuitem menu { border-radius: 0; padding: 0; }
 
-menubar > menuitem menu menu, .menubar > menuitem menu menu { border-radius: 5px; }
+menubar > menuitem menu menu, .menubar > menuitem menu menu { border-radius: 0; padding: 0; }
 
 menubar > menuitem:hover, .menubar > menuitem:hover { box-shadow: inset 0 -3px #15539e; color: #3584e4; }
 
 menubar > menuitem:disabled, .menubar > menuitem:disabled { color: #919190; box-shadow: none; }
 
+menubar .csd.popup decoration, .menubar .csd.popup decoration { border-radius: 0; }
+
 .background.popup { background-color: transparent; }
 
 menu, .menu, .context-menu { margin: 4px; padding: 4px 0px; background-color: #2f2f2f; border: 1px solid #1b1b1b; border-radius: 5px; }
diff --git a/gtk/theme/Adwaita/gtk-contained.css b/gtk/theme/Adwaita/gtk-contained.css
index 93de81f114..f34038aaba 100644
--- a/gtk/theme/Adwaita/gtk-contained.css
+++ b/gtk/theme/Adwaita/gtk-contained.css
@@ -809,14 +809,16 @@ menubar:backdrop, .menubar:backdrop { background-color: #f6f5f4; }
 
 menubar > menuitem, .menubar > menuitem { min-height: 16px; padding: 4px 8px; }
 
-menubar > menuitem menu, .menubar > menuitem menu { border-radius: 0 0 5px 5px; }
+menubar > menuitem menu, .menubar > menuitem menu { border-radius: 0; padding: 0; }
 
-menubar > menuitem menu menu, .menubar > menuitem menu menu { border-radius: 5px; }
+menubar > menuitem menu menu, .menubar > menuitem menu menu { border-radius: 0; padding: 0; }
 
 menubar > menuitem:hover, .menubar > menuitem:hover { box-shadow: inset 0 -3px #3584e4; color: #1b6acb; }
 
 menubar > menuitem:disabled, .menubar > menuitem:disabled { color: #929595; box-shadow: none; }
 
+menubar .csd.popup decoration, .menubar .csd.popup decoration { border-radius: 0; }
+
 .background.popup { background-color: transparent; }
 
 menu, .menu, .context-menu { margin: 4px; padding: 4px 0px; background-color: #ffffff; border: 1px solid #cdc7c2; border-radius: 5px; }