diff --git a/includes/SkinVector.php b/includes/SkinVector.php
index ab199d6f6..a55625379 100644
--- a/includes/SkinVector.php
+++ b/includes/SkinVector.php
@@ -779,6 +779,9 @@ abstract class SkinVector extends SkinMustache {
 			self::MENU_TYPE_PORTAL => 'vector-menu vector-menu-portal portal',
 			self::MENU_TYPE_DEFAULT => 'vector-menu',
 		];
+		if ( $this->isLegacy() ) {
+			$extraClasses[self::MENU_TYPE_TABS] .= ' vector-menu-tabs-legacy';
+		}
 		$portletData['heading-class'] = '';
 		// Add target class to apply different icon to personal menu dropdown for logged in users.
 		if ( $portletData['id'] === 'p-personal' ) {
diff --git a/includes/templates/legacy/Sidebar.mustache b/includes/templates/legacy/Sidebar.mustache
index 69dbcf4bd..9556f9100 100644
--- a/includes/templates/legacy/Sidebar.mustache
+++ b/includes/templates/legacy/Sidebar.mustache
@@ -7,7 +7,7 @@
 		<a class="mw-wiki-logo" href="{{link-mainpage}}"
 			title="{{msg-tooltip-p-logo}}"></a>
 	</div>
-	{{#data-portlets-first}}{{>legacy/Menu}}{{/data-portlets-first}}
-	{{#array-portlets-rest}}{{>legacy/Menu}}{{/array-portlets-rest}}
-	{{#data-portlets.data-languages}}{{>legacy/Menu}}{{/data-portlets.data-languages}}
+	{{#data-portlets-first}}{{>Menu}}{{/data-portlets-first}}
+	{{#array-portlets-rest}}{{>Menu}}{{/array-portlets-rest}}
+	{{#data-portlets.data-languages}}{{>Menu}}{{/data-portlets.data-languages}}
 </div>
diff --git a/resources/skins.vector.styles.legacy/components/MenuTabs.less b/resources/skins.vector.styles.legacy/components/MenuTabs.less
index 0d61bd2da..71f5ccf09 100644
--- a/resources/skins.vector.styles.legacy/components/MenuTabs.less
+++ b/resources/skins.vector.styles.legacy/components/MenuTabs.less
@@ -6,7 +6,9 @@
  */
 
 /* Namespaces and Views */
-.vector-menu-tabs {
+// FIXME: Remove vector-menu-tabs when vector-menu-tabs-legacy is present everywhere
+.vector-menu-tabs,
+.vector-menu-tabs-legacy {
 	// Tab separator: Outer start border (left in LTR) of tab row.
 	background-position: left bottom;
 	float: left;
diff --git a/tests/phpunit/integration/SkinVectorTest.php b/tests/phpunit/integration/SkinVectorTest.php
index 915cefa6d..5e8a881cf 100644
--- a/tests/phpunit/integration/SkinVectorTest.php
+++ b/tests/phpunit/integration/SkinVectorTest.php
@@ -255,7 +255,8 @@ class SkinVectorTest extends MediaWikiIntegrationTestCase {
 			[
 				// Provided by core
 				'id' => 'p-views',
-				'class' => 'mw-portlet mw-portlet-views emptyPortlet vector-menu vector-menu-tabs',
+				'class' => 'mw-portlet mw-portlet-views emptyPortlet ' .
+					'vector-menu vector-menu-tabs vector-menu-tabs-legacy',
 				'html-tooltip' => '',
 				'html-items' => '',
 				'html-after-portal' => '',
@@ -270,7 +271,7 @@ class SkinVectorTest extends MediaWikiIntegrationTestCase {
 		$variants = $props['data-variants'];
 		$actions = $props['data-actions'];
 		$this->assertSame(
-			'mw-portlet mw-portlet-namespaces vector-menu vector-menu-tabs',
+			'mw-portlet mw-portlet-namespaces vector-menu vector-menu-tabs vector-menu-tabs-legacy',
 			$namespaces['class']
 		);
 		$this->assertSame(