diff --git a/analytics/views.py b/analytics/views.py
index 7e9f10b4b9..3f48f187ec 100644
--- a/analytics/views.py
+++ b/analytics/views.py
@@ -1,5 +1,6 @@
 from __future__ import absolute_import
 from __future__ import division
+from six import text_type
 from typing import Any, Dict, List, Tuple, Optional, Sequence, Callable, Union
 
 from django.db import connection
@@ -790,7 +791,7 @@ def user_activity_summary_table(user_summary):
     return make_table(title, cols, rows)
 
 def realm_user_summary_table(all_records, admin_emails):
-    # type: (List[QuerySet], Set[str]) -> Tuple[Dict[str, Dict[str, Any]], str]
+    # type: (List[QuerySet], Set[text_type]) -> Tuple[Dict[str, Dict[str, Any]], str]
     user_records = {}
 
     def by_email(record):
diff --git a/zerver/lib/actions.py b/zerver/lib/actions.py
index 402c2f4ad3..e479e8c1d0 100644
--- a/zerver/lib/actions.py
+++ b/zerver/lib/actions.py
@@ -2347,7 +2347,7 @@ def do_update_message(user_profile, message_id, subject, propagate_mode, content
 
     event = {'type': 'update_message',
              'sender': user_profile.email,
-             'message_id': message_id}
+             'message_id': message_id} # type: Dict[str, Any]
     edit_history_event = {}
     changed_messages = [message]
 
diff --git a/zerver/lib/upload.py b/zerver/lib/upload.py
index 7b2e903303..3f85217291 100644
--- a/zerver/lib/upload.py
+++ b/zerver/lib/upload.py
@@ -92,7 +92,7 @@ class ZulipUploadBackend(object):
         raise NotImplementedError()
 
     def upload_avatar_image(self, user_file, user_profile, email):
-        # type: (File, UserProfile, str) -> None
+        # type: (File, UserProfile, text_type) -> None
         raise NotImplementedError()
 
     def delete_message_image(self, path_id):
@@ -200,7 +200,7 @@ class S3UploadBackend(ZulipUploadBackend):
         return False
 
     def upload_avatar_image(self, user_file, user_profile, email):
-        # type: (File, UserProfile, str) -> None
+        # type: (File, UserProfile, text_type) -> None
         content_type = guess_type(user_file.name)[0]
         bucket_name = settings.S3_AVATAR_BUCKET
         s3_file_name = user_avatar_hash(email)
@@ -275,7 +275,7 @@ class LocalUploadBackend(ZulipUploadBackend):
         return False
 
     def upload_avatar_image(self, user_file, user_profile, email):
-        # type: (File, UserProfile, str) -> None
+        # type: (File, UserProfile, text_type) -> None
         email_hash = user_avatar_hash(email)
 
         image_data = user_file.read()
@@ -295,7 +295,7 @@ def delete_message_image(path_id):
     return upload_backend.delete_message_image(path_id)
 
 def upload_avatar_image(user_file, user_profile, email):
-    # type: (File, UserProfile, str) -> None
+    # type: (File, UserProfile, text_type) -> None
     upload_backend.upload_avatar_image(user_file, user_profile, email)
 
 def upload_message_image(uploaded_file_name, content_type, file_data, user_profile, target_realm=None):