diff --git a/zerver/models.py b/zerver/models.py
index 9703ac6cdc..99eacf0a29 100644
--- a/zerver/models.py
+++ b/zerver/models.py
@@ -147,16 +147,20 @@ class Realm(models.Model):
     DEFAULT_NOTIFICATION_STREAM_NAME = 'announce'
 
     def __repr__(self):
+        # type: () -> str
         return (u"<Realm: %s %s>" % (self.domain, self.id)).encode("utf-8")
     def __str__(self):
+        # type: () -> str
         return self.__repr__()
 
     @cache_with_key(get_realm_emoji_cache_key, timeout=3600*24*7)
     def get_emoji(self):
+        # type: () -> Dict[str, Dict[str, str]]
         return get_realm_emoji_uncached(self)
 
     @property
     def deployment(self):
+        # type: () -> Any # returns a Deployment from zilencer.models
         try:
             return self._deployments.all()[0]
         except IndexError:
@@ -254,6 +258,7 @@ class RealmEmoji(models.Model):
         unique_together = ("realm", "name")
 
     def __str__(self):
+        # type: () -> str
         return "<RealmEmoji(%s): %s %s>" % (self.realm.domain, self.name, self.img_url)
 
 def get_realm_emoji_uncached(realm):
@@ -283,6 +288,7 @@ class RealmFilter(models.Model):
         unique_together = ("realm", "pattern")
 
     def __str__(self):
+        # type: () -> str
         return "<RealmFilter(%s): %s %s>" % (self.realm.domain, self.pattern, self.url_format_string)
 
 def get_realm_filters_cache_key(domain):
@@ -452,8 +458,10 @@ class UserProfile(AbstractBaseUser, PermissionsMixin):
         return self.last_reminder
 
     def __repr__(self):
+        # type: () -> str
         return (u"<UserProfile: %s %s>" % (self.email, self.realm)).encode("utf-8")
     def __str__(self):
+        # type: () -> str
         return self.__repr__()
 
     @staticmethod
@@ -541,8 +549,10 @@ class Stream(models.Model):
     deactivated = models.BooleanField(default=False)
 
     def __repr__(self):
+        # type: () -> str
         return (u"<Stream: %s>" % (self.name,)).encode("utf-8")
     def __str__(self):
+        # type: () -> str
         return self.__repr__()
 
     def is_public(self):
@@ -617,6 +627,7 @@ class Recipient(models.Model):
         return self._type_names[self.type]
 
     def __repr__(self):
+        # type: () -> str
         display_recipient = get_display_recipient(self)
         return (u"<Recipient: %s (%d, %s)>" % (display_recipient, self.type_id, self.type)).encode("utf-8")
 
@@ -624,7 +635,8 @@ class Client(models.Model):
     name = models.CharField(max_length=30, db_index=True, unique=True)
 
     def __repr__(self):
-        return u"<Client: %s>" % (self.name,)
+        # type: () -> str
+        return "<Client: %s>" % (self.name,)
 
 get_client_cache = {} # type: Dict[str, Client]
 def get_client(name):
@@ -678,6 +690,8 @@ def bulk_get_streams(realm, stream_names):
         realm_id = realm
 
     def fetch_streams_by_name(stream_names):
+        # type: (List[str]) -> List[str]
+        #
         # This should be just
         #
         # Stream.objects.select_related("realm").filter(name__iexact__in=stream_names,
@@ -710,8 +724,10 @@ def get_recipient(type, type_id):
 def bulk_get_recipients(type, type_ids):
     # type: (int, List[int]) -> Dict[int, Any]
     def cache_key_function(type_id):
+        # type: (int) -> str
         return get_recipient_cache_key(type, type_id)
     def query_function(type_ids):
+        # type: (List[int]) -> List[Recipient]
         return Recipient.objects.filter(type=type, type_id__in=type_ids)
 
     return generic_bulk_cached_fetch(cache_key_function, query_function, type_ids,
@@ -755,9 +771,11 @@ class Message(models.Model):
 
 
     def __repr__(self):
+        # type: () -> str
         display_recipient = get_display_recipient(self.recipient)
         return (u"<Message: %s / %s / %r>" % (display_recipient, self.subject, self.sender)).encode("utf-8")
     def __str__(self):
+        # type: () -> str
         return self.__repr__()
 
     def get_realm(self):
@@ -1136,6 +1154,7 @@ class UserMessage(models.Model):
         unique_together = ("user_profile", "message")
 
     def __repr__(self):
+        # type: () -> str
         display_recipient = get_display_recipient(self.message.recipient)
         return (u"<UserMessage: %s / %s (%s)>" % (display_recipient, self.user_profile.email, self.flags_list())).encode("utf-8")
 
@@ -1165,6 +1184,7 @@ class Attachment(models.Model):
     create_time = models.DateTimeField(default=timezone.now, db_index=True)
 
     def __repr__(self):
+        # type: () -> str
         return (u"<Attachment: %s>" % (self.file_name))
 
     def is_claimed(self):
@@ -1211,8 +1231,10 @@ class Subscription(models.Model):
         unique_together = ("user_profile", "recipient")
 
     def __repr__(self):
+        # type: () -> str
         return (u"<Subscription: %r -> %s>" % (self.user_profile, self.recipient)).encode("utf-8")
     def __str__(self):
+        # type: () -> str
         return self.__repr__()
 
 @cache_with_key(user_profile_by_id_cache_key, timeout=3600*24*7)