diff --git a/includes/templates/Menu.mustache b/includes/templates/Menu.mustache
index c0c488438..0bbe7cd4a 100644
--- a/includes/templates/Menu.mustache
+++ b/includes/templates/Menu.mustache
@@ -2,7 +2,7 @@
 	See @typedef MenuDefinition
 }}
 {{! `role` is unnecessary but kept to support selectors in any gadgets or user styles. }}
-<nav id="{{id}}"{{#class}} class="{{.}}"{{/class}} aria-labelledby="{{id}}-label" role="navigation" {{{html-tooltip}}}
+<nav id="{{id}}" class="{{#class}}{{.}} {{/class}}{{#is-dropdown}}vector-menu-dropdown{{/is-dropdown}}" aria-labelledby="{{id}}-label" role="navigation" {{{html-tooltip}}}
 	 {{{html-user-language-attributes}}}>
 	{{#is-dropdown}}
 	<input type="checkbox"
diff --git a/resources/skins.vector.js/dropdownMenus.js b/resources/skins.vector.js/dropdownMenus.js
index e06745c8f..a605baecb 100644
--- a/resources/skins.vector.js/dropdownMenus.js
+++ b/resources/skins.vector.js/dropdownMenus.js
@@ -1,3 +1,34 @@
+/** @interface CheckboxHack */
+
+var
+	checkboxHack = /** @type {CheckboxHack} */ require( /** @type {string} */( 'mediawiki.page.ready' ) ).checkboxHack,
+	CHECKBOX_HACK_CONTAINER_SELECTOR = '.vector-menu-dropdown',
+	CHECKBOX_HACK_CHECKBOX_SELECTOR = '.vector-menu-checkbox',
+	CHECKBOX_HACK_BUTTON_SELECTOR = '.vector-menu-checkbox',
+	CHECKBOX_HACK_TARGET_SELECTOR = '.vector-menu-content';
+
+/**
+ * Add the ability for users to toggle dropdown menus using the enter key (as
+ * well as space) using core's checkboxHack.
+ */
+function bindToggleOnSpaceEnter() {
+	// Search for all dropdown containers using the CHECKBOX_HACK_CONTAINER_SELECTOR.
+	var containers = document.querySelectorAll( CHECKBOX_HACK_CONTAINER_SELECTOR );
+
+	Array.prototype.forEach.call( containers, function ( container ) {
+		var
+			checkbox = container.querySelector( CHECKBOX_HACK_CHECKBOX_SELECTOR ),
+			button = container.querySelector( CHECKBOX_HACK_BUTTON_SELECTOR ),
+			target = container.querySelector( CHECKBOX_HACK_TARGET_SELECTOR );
+
+		if ( !( checkbox && button && target ) ) {
+			return;
+		}
+
+		checkboxHack.bindToggleOnSpaceEnter( checkbox, button );
+	} );
+}
+
 /**
  * Make sure that clicking outside a menu closes it.
  */
@@ -63,4 +94,5 @@ mw.hook( 'util.addPortletLink' ).add( addPortletLinkHandler );
 
 module.exports = function dropdownMenus() {
 	closeDropdownsOnClickOutside();
+	bindToggleOnSpaceEnter();
 };
diff --git a/resources/skins.vector.js/skin.js b/resources/skins.vector.js/skin.js
index 431102b27..617d0320b 100644
--- a/resources/skins.vector.js/skin.js
+++ b/resources/skins.vector.js/skin.js
@@ -47,7 +47,6 @@ function main( window ) {
 	enableCssAnimations( window.document );
 	collapsibleTabs.init();
 	sidebar.init( window );
-	dropdownMenus();
 	vector.init();
 	initSearchLoader( document );
 	// Initialize the search toggle for the main header only. The sticky header
@@ -55,6 +54,10 @@ function main( window ) {
 	searchToggle( document.querySelector( '.mw-header .search-toggle' ) );
 	languageButton();
 	stickyHeader();
+	// dropdownMenus should be placed afer sticky header is initialized in order to
+	// bind the correct event handlers to the sticky header dropdown menus (e.g.
+	// user menu).
+	dropdownMenus();
 }
 
 /**