diff --git a/endpoints/api/user.py b/endpoints/api/user.py
index 93e77f47c..b03c5f87b 100644
--- a/endpoints/api/user.py
+++ b/endpoints/api/user.py
@@ -444,19 +444,19 @@ class ConvertToOrganization(ApiResource):
     user = get_authenticated_user()
     convert_data = request.get_json()
 
-    # Ensure that the new admin user is the not user being converted.
-    admin_username = convert_data['adminUser']
-    if admin_username == user.username:
-      raise request_error(reason='invaliduser',
-                           message='The admin user is not valid')
-
     # Ensure that the sign in credentials work.
+    admin_username = convert_data['adminUser']
     admin_password = convert_data['adminPassword']
     (admin_user, error_message) =  authentication.verify_user(admin_username, admin_password)
     if not admin_user:
       raise request_error(reason='invaliduser',
                            message='The admin user credentials are not valid')
 
+    # Ensure that the new admin user is the not user being converted.
+    if admin_user.id == user.id:
+      raise request_error(reason='invaliduser',
+                           message='The admin user is not valid')
+
     # Subscribe the organization to the new plan.
     if features.BILLING:
       plan = convert_data.get('plan', 'free')
diff --git a/test/test_api_usage.py b/test/test_api_usage.py
index d82d344e4..6123aa1cc 100644
--- a/test/test_api_usage.py
+++ b/test/test_api_usage.py
@@ -307,6 +307,16 @@ class TestConvertToOrganization(ApiTestCase):
 
     self.assertEqual('The admin user is not valid', json['message'])
 
+  def test_sameadminuser_by_email(self):
+    self.login(READ_ACCESS_USER)
+    json = self.postJsonResponse(ConvertToOrganization,
+                                 data={'adminUser': 'no1@thanks.com',
+                                       'adminPassword': 'password',
+                                       'plan': 'free'},
+                                 expected_code=400)
+
+    self.assertEqual('The admin user is not valid', json['message'])
+
   def test_invalidadminuser(self):
     self.login(READ_ACCESS_USER)
     json = self.postJsonResponse(ConvertToOrganization,