diff --git a/zerver/tests/test_bots.py b/zerver/tests/test_bots.py
index 7f6afc690b..76a48363fa 100644
--- a/zerver/tests/test_bots.py
+++ b/zerver/tests/test_bots.py
@@ -226,6 +226,7 @@ class BotTest(ZulipTestCase):
         self.login("hamlet@zulip.com")
         user_profile = get_user_profile_by_email("hamlet@zulip.com")
         stream = get_stream("Denmark", user_profile.realm)
+        assert stream is not None
         self.subscribe_to_stream(user_profile.email, stream.name)
         do_change_stream_invite_only(stream, True)
 
@@ -264,6 +265,7 @@ class BotTest(ZulipTestCase):
         self.login("hamlet@zulip.com")
         user_profile = get_user_profile_by_email("hamlet@zulip.com")
         stream = get_stream("Denmark", user_profile.realm)
+        assert stream is not None
         self.unsubscribe_from_stream("hamlet@zulip.com", "Denmark")
         do_change_stream_invite_only(stream, True)
 
@@ -328,6 +330,7 @@ class BotTest(ZulipTestCase):
         self.login("hamlet@zulip.com")
         user_profile = get_user_profile_by_email("hamlet@zulip.com")
         stream = get_stream("Denmark", user_profile.realm)
+        assert stream is not None
         self.unsubscribe_from_stream("hamlet@zulip.com", "Denmark")
         do_change_stream_invite_only(stream, True)
 
@@ -625,6 +628,7 @@ class BotTest(ZulipTestCase):
         self.login("hamlet@zulip.com")
         user_profile = get_user_profile_by_email("hamlet@zulip.com")
         stream = get_stream("Denmark", user_profile.realm)
+        assert stream is not None
         self.unsubscribe_from_stream("hamlet@zulip.com", "Denmark")
         do_change_stream_invite_only(stream, True)
 
@@ -707,6 +711,7 @@ class BotTest(ZulipTestCase):
         self.login("hamlet@zulip.com")
         user_profile = get_user_profile_by_email("hamlet@zulip.com")
         stream = get_stream("Denmark", user_profile.realm)
+        assert stream is not None
         self.unsubscribe_from_stream("hamlet@zulip.com", "Denmark")
         do_change_stream_invite_only(stream, True)