diff --git a/gapi.auth2/gapi.auth2-tests.ts b/gapi.auth2/gapi.auth2-tests.ts
index 15fd8b4e2b..621ca6f056 100644
--- a/gapi.auth2/gapi.auth2-tests.ts
+++ b/gapi.auth2/gapi.auth2-tests.ts
@@ -26,6 +26,15 @@ function test_signIn(){
   });
 }
 
+function test_signInOptionsBuild(){
+  var options = new gapi.auth2.SigninOptionsBuilder();
+  options.setAppPackageName('com.example.app');
+  options.setFetchBasicProfile(true);
+  options.setPrompt('select_account');
+  options.setScope('profile').setScope('email');
+  gapi.auth2.getAuthInstance().signIn(options);
+}
+
 function test_getAuthResponse(){
   var user = gapi.auth2.getAuthInstance().currentUser.get();
   var authResponse = user.getAuthResponse();
diff --git a/gapi.auth2/index.d.ts b/gapi.auth2/index.d.ts
index c30f37d013..6146a87e28 100644
--- a/gapi.auth2/index.d.ts
+++ b/gapi.auth2/index.d.ts
@@ -31,12 +31,7 @@ declare namespace gapi.auth2 {
     /**
      * Signs in the user using the specified options.
      */
-    signIn(options?: {
-      app_package_name?: string;
-      fetch_basic_profile?: boolean;
-      prompt?: string;
-      scope?: string;
-    }, optionBuilder?: SigninOptionsBuilder): any;
+    signIn(options?: SigninOptions | SigninOptionsBuilder): any;
 
     /**
      * Signs out all accounts from the application.
@@ -59,12 +54,8 @@ declare namespace gapi.auth2 {
     /**
      * Attaches the sign-in flow to the specified container's click handler.
      */
-    attachClickHandler(container: any, options: {
-      app_package_name?: string;
-      fetch_basic_profile?: boolean;
-      prompt?: string;
-      scope?: string;
-    }, onsuccess: (googleUser: GoogleUser) => any, onfailure: (reason: string) => any): any;
+    attachClickHandler(container: any, options: SigninOptions,
+                       onsuccess: (googleUser: GoogleUser) => any, onfailure: (reason: string) => any): any;
   }
 
   export interface IsSignedIn{
@@ -93,6 +84,32 @@ declare namespace gapi.auth2 {
     listen(listener: (user: GoogleUser) => any): void;
   }
 
+  export interface SigninOptions {
+    /**
+     * The package name of the Android app to install over the air.
+     * See Android app installs from your web site:
+     * https://developers.google.com/identity/sign-in/web/android-app-installs
+     */
+    app_package_name?: string;
+    /**
+     * 	Fetch users' basic profile information when they sign in.
+     * 	Adds 'profile', 'email' and 'openid' to the requested scopes.
+     * 	True if unspecified.
+     */
+    fetch_basic_profile?: boolean;
+    /**
+     * Specifies whether to prompt the user for re-authentication.
+     * See OpenID Connect Request Parameters:
+     * https://openid.net/specs/openid-connect-basic-1_0.html#RequestParameters
+     */
+    prompt?: string;
+    /**
+     * The scopes to request, as a space-delimited string.
+     * Optional if fetch_basic_profile is not set to false.
+     */
+    scope?: string;
+  }
+
   export class SigninOptionsBuilder {
     setAppPackageName(name: string): any;
     setFetchBasicProfile(fetch: boolean): any;
@@ -164,22 +181,12 @@ declare namespace gapi.auth2 {
      * When you use GoogleUser.signIn(), the sign-in flow skips the account chooser step.
      * See GoogleAuth.signIn().
      */
-    signIn(options?: {
-      app_package_name?: string;
-      fetch_basic_profile?: boolean;
-      prompt?: string;
-      scope?: string;
-    }, optionBuilder?: SigninOptionsBuilder): any;
+    signIn(options?: SigninOptions | SigninOptionsBuilder): any;
 
     /**
-     *
+     * See GoogleUser.signIn()
      */
-    grant(options?: {
-      app_package_name?: string;
-      fetch_basic_profile?: boolean;
-      prompt?: string;
-      scope?: string;
-    }, optionBuilder?: SigninOptionsBuilder): any;
+    grant(options?: SigninOptions | SigninOptionsBuilder): any;
 
     /**
      * Get permission from the user to access the specified scopes offline.