diff --git a/zerver/lib/actions.py b/zerver/lib/actions.py
index 9d670402d9..22e828cc94 100644
--- a/zerver/lib/actions.py
+++ b/zerver/lib/actions.py
@@ -422,9 +422,11 @@ def active_humans_in_realm(realm):
 
 
 def do_set_realm_property(realm, name, value):
-    # type: (Realm, Text, Union[Text, bool, int]) -> None
+    # type: (Realm, str, Union[Text, bool, int]) -> None
     """Takes in a realm object, the name of an attribute to update, and the value to update.
     """
+    property_type = Realm.property_types[name]
+    assert isinstance(value, property_type)
     setattr(realm, name, value)
     realm.save(update_fields=[name])
     event = dict(
diff --git a/zerver/models.py b/zerver/models.py
index 3d87701c63..bd11f943ba 100644
--- a/zerver/models.py
+++ b/zerver/models.py
@@ -144,6 +144,23 @@ class Realm(ModelReprMixin, models.Model):
                                       default=2**31 - 1) # type: BitHandler
     waiting_period_threshold = models.PositiveIntegerField(default=0) # type: int
 
+    # Define the types of the various automatically managed properties
+    property_types = dict(
+        add_emoji_by_admins_only=bool,
+        create_stream_by_admins_only=bool,
+        default_language=Text,
+        description=Text,
+        email_changes_disabled=bool,
+        invite_required=bool,
+        invite_by_admins_only=bool,
+        inline_image_preview=bool,
+        inline_url_embed_preview=bool,
+        name=Text,
+        name_changes_disabled=bool,
+        restricted_to_domain=bool,
+        waiting_period_threshold=int,
+    )
+
     ICON_FROM_GRAVATAR = u'G'
     ICON_UPLOADED = u'U'
     ICON_SOURCES = (