diff --git a/packages-exp/auth-exp/src/platform_browser/recaptcha/recaptcha_loader.test.ts b/packages-exp/auth-exp/src/platform_browser/recaptcha/recaptcha_loader.test.ts
index 4683bf1125e..b1323c55e63 100644
--- a/packages-exp/auth-exp/src/platform_browser/recaptcha/recaptcha_loader.test.ts
+++ b/packages-exp/auth-exp/src/platform_browser/recaptcha/recaptcha_loader.test.ts
@@ -67,9 +67,9 @@ describe('platform_browser/recaptcha/recaptcha_loader', () => {
       triggerNetworkTimeout = stubSingleTimeout(networkTimeoutId);
 
       sinon.stub(jsHelpers, '_loadJS').callsFake(() => {
-        return new Promise((resolve, reject) => {
+        return (new Promise<void>((resolve, reject) => {
           jsLoader = { resolve, reject };
-        });
+        }) as unknown) as Promise<Event>;
       });
 
       loader = new ReCaptchaLoaderImpl();