diff --git a/selenium-webdriver/index.d.ts b/selenium-webdriver/index.d.ts
index 7c960b3d25..b8acad06d4 100644
--- a/selenium-webdriver/index.d.ts
+++ b/selenium-webdriver/index.d.ts
@@ -2319,7 +2319,7 @@ declare namespace webdriver {
              *     resolved with the result of the invoked callback.
              * @template R
              */
-            then<R>(opt_callback?: (value: T) => R|IThenable<R>, opt_errback?: (error: any) => R|IThenable<R>): Promise<R>;
+            then<R>(opt_callback?: (value: T) => R|IThenable<R>, opt_errback?: (error: any) => any): Promise<R>;
 
             /**
              * Registers a listener for when this promise is rejected. This is synonymous
@@ -2526,7 +2526,7 @@ declare namespace webdriver {
              * @return A new promise which will be resolved
              *     with the result of the invoked callback.
              */
-            then(opt_callback?: Function, opt_errback?: Function): Promise<any>;
+            then<R>(opt_callback?: (value: T) => IThenable<R>|R, opt_errback?: (error: any) => any): Promise<R>;
 
             /**
              * Registers a listener for when this promise is rejected. This is synonymous
diff --git a/selenium-webdriver/selenium-webdriver-tests.ts b/selenium-webdriver/selenium-webdriver-tests.ts
index cab1443471..4e3aa348a3 100644
--- a/selenium-webdriver/selenium-webdriver-tests.ts
+++ b/selenium-webdriver/selenium-webdriver-tests.ts
@@ -1114,6 +1114,10 @@ function TestErrorCode() {
     errorCode = new webdriver.error.UnknownMethodError().code();
     errorCode = new webdriver.error.UnsupportedOperationError().code();
 }
+async function TestAsyncAwaitable() {
+    var thenable: webdriver.promise.Promise<string> = new webdriver.promise.Promise<string>();
+    var str: string = await thenable;
+}
 
 function TestTestingModule() {
     testing.before(function () {