diff --git a/zulip_botserver/tests/server_test_lib.py b/zulip_botserver/tests/server_test_lib.py
index cb365c5..2fb3538 100644
--- a/zulip_botserver/tests/server_test_lib.py
+++ b/zulip_botserver/tests/server_test_lib.py
@@ -1,5 +1,6 @@
 import configparser
 import json
+import mock
 
 from typing import Any, List, Dict, Optional
 from unittest import TestCase
@@ -12,8 +13,10 @@ class BotServerTestCase(TestCase):
         server.app.testing = True
         self.app = server.app.test_client()
 
+    @mock.patch('zulip_bots.lib.ExternalBotHandler')
     def assert_bot_server_response(
         self,
+        mock_ExternalBotHandler: mock.Mock,
         available_bots: Optional[List[str]]=None,
         bots_config: Optional[Dict[str, Dict[str, str]]]=None,
         bot_handlers: Optional[Dict[str, Any]]=None,
diff --git a/zulip_botserver/tests/test_server.py b/zulip_botserver/tests/test_server.py
index 964922b..95c3cd4 100644
--- a/zulip_botserver/tests/test_server.py
+++ b/zulip_botserver/tests/test_server.py
@@ -19,8 +19,7 @@ class BotServerTests(BotServerTestCase):
         def handler_class(self) -> Any:
             return BotServerTests.MockMessageHandler()
 
-    @mock.patch('zulip_bots.lib.ExternalBotHandler')
-    def test_successful_request(self, mock_ExternalBotHandler: mock.Mock) -> None:
+    def test_successful_request(self) -> None:
         available_bots = ['helloworld']
         bots_config = {
             'helloworld': {
@@ -35,8 +34,7 @@ class BotServerTests(BotServerTestCase):
                                                    bot_email='helloworld-bot@zulip.com'),
                                         check_success=True)
 
-    @mock.patch('zulip_bots.lib.ExternalBotHandler')
-    def test_successful_request_from_two_bots(self, mock_ExternalBotHandler: mock.Mock) -> None:
+    def test_successful_request_from_two_bots(self) -> None:
         available_bots = ['helloworld', 'help']
         bots_config = {
             'helloworld': {