diff --git a/b2g/components/test/unit/test_fxaccounts.js b/b2g/components/test/unit/test_fxaccounts.js
index 63ebfce20902..be45ed3b957f 100644
--- a/b2g/components/test/unit/test_fxaccounts.js
+++ b/b2g/components/test/unit/test_fxaccounts.js
@@ -11,8 +11,11 @@ Cu.import("resource://services-common/utils.js");
 Cu.import("resource://testing-common/httpd.js");
 
 XPCOMUtils.defineLazyModuleGetter(this, "FxAccountsMgmtService",
-                                  "resource://gre/modules/FxAccountsMgmtService.jsm",
-                                  "FxAccountsMgmtService");
+  "resource://gre/modules/FxAccountsMgmtService.jsm",
+  "FxAccountsMgmtService");
+
+XPCOMUtils.defineLazyModuleGetter(this, "FxAccountsManager",
+  "resource://gre/modules/FxAccountsManager.jsm");
 
 // At end of test, restore original state
 const ORIGINAL_AUTH_URI = Services.prefs.getCharPref("identity.fxaccounts.auth.uri");
@@ -158,6 +161,22 @@ add_test(function test_invalidEmailCase_signIn() {
   });
 });
 
+add_test(function testHandleGetAssertionError_defaultCase() {
+  do_test_pending();
+
+  FxAccountsManager.getAssertion(null).then(
+    success => {
+      // getAssertion should throw with invalid audience
+      ok(false);
+    },
+    reason => {
+      equal("INVALID_AUDIENCE", reason.error);
+      do_test_finished();
+      run_next_test();
+    }
+  )
+});
+
 // End of tests
 // Utility functions follow
 
diff --git a/services/fxaccounts/FxAccountsManager.jsm b/services/fxaccounts/FxAccountsManager.jsm
index 0baae63635f6..c3609ee91c86 100644
--- a/services/fxaccounts/FxAccountsManager.jsm
+++ b/services/fxaccounts/FxAccountsManager.jsm
@@ -204,7 +204,7 @@ this.FxAccountsManager = {
         }
       );
     }
-    return rejection;
+    return Promise.reject(reason);
   },
 
   _getAssertion: function(aAudience) {