Index: src/wp-admin/css/admin-menu.css
===================================================================
--- src/wp-admin/css/admin-menu.css	(revision 29206)
+++ src/wp-admin/css/admin-menu.css	(working copy)
@@ -480,12 +480,6 @@
 	cursor: inherit;
 }
 
-/* @todo: is this even needed given that it's nested beneath the above li.wp-menu-separator? */
-#adminmenu div.separator {
-	height: 2px;
-	padding: 0;
-}
-
 #adminmenu .wp-submenu .wp-submenu-head {
 	color: #fff;
 	font-weight: 400;
Index: src/wp-admin/menu-header.php
===================================================================
--- src/wp-admin/menu-header.php	(revision 29206)
+++ src/wp-admin/menu-header.php	(working copy)
@@ -106,9 +106,7 @@
 
 		echo "\n\t<li$class$id>";
 
-		if ( false !== strpos( $class, 'wp-menu-separator' ) ) {
-			echo '<div class="separator"></div>';
-		} elseif ( $submenu_as_parent && ! empty( $submenu_items ) ) {
+		if ( $submenu_as_parent && ! empty( $submenu_items ) ) {
 			$submenu_items = array_values( $submenu_items );  // Re-index.
 			$menu_hook = get_plugin_page_hook( $submenu_items[0][2], $item[2] );
 			$menu_file = $submenu_items[0][2];