diff --git a/jquery/updateTooltipAccessKeys.d.ts b/jquery/updateTooltipAccessKeys.d.ts
new file mode 100644
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--- /dev/null
+++ b/jquery/updateTooltipAccessKeys.d.ts
@@ -0,0 +1,45 @@
+import { Navigator } from "./client";
+
+declare global {
+    interface JQuery {
+        updateTooltipAccessKeys: TooltipAccessKeys<this>;
+    }
+}
+
+type Modifier = "alt" | "alt-shift" | "ctrl" | "ctrl-option";
+
+interface TooltipAccessKeys<This = JQuery> {
+    /**
+     * Update the titles for all elements in a jQuery selection.
+     *
+     * @returns {JQuery}
+     */
+    (): This;
+
+    /**
+     * Get the access key label for an element.
+     *
+     * Will use native accessKeyLabel if available (currently only in Firefox 8+),
+     * falls back to #getAccessKeyModifiers.
+     *
+     * @param {HTMLElement} element Element to get the label for
+     * @returns {string} Access key label
+     */
+    // result may be HTMLElement.accessKeyLabel, the format of which depend very much on the browser.
+    getAccessKeyLabel(element: HTMLElement): string;
+
+    /**
+     * @param {Navigator} [nav] An object with a 'userAgent' and 'platform' property.
+     * @returns {string}
+     */
+    getAccessKeyPrefix(nav?: Navigator): `${Modifier}-`;
+
+    /**
+     * Switch test mode on and off.
+     *
+     * @param {boolean} mode New mode
+     */
+    setTestMode(mode: boolean): void;
+}
+
+export {};