diff --git a/synapse/appservice/__init__.py b/synapse/appservice/__init__.py
index 63a18b802..e3ca45de8 100644
--- a/synapse/appservice/__init__.py
+++ b/synapse/appservice/__init__.py
@@ -148,8 +148,8 @@ class ApplicationService(object):
                 and self.is_interested_in_user(event.state_key)):
             return True
         # check joined member events
-        for member in member_list:
-            if self.is_interested_in_user(member.state_key):
+        for user_id in member_list:
+            if self.is_interested_in_user(user_id):
                 return True
         return False
 
@@ -173,7 +173,7 @@ class ApplicationService(object):
             restrict_to(str): The namespace to restrict regex tests to.
             aliases_for_event(list): A list of all the known room aliases for
             this event.
-            member_list(list): A list of all joined room members in this room.
+            member_list(list): A list of all joined user_ids in this room.
         Returns:
             bool: True if this service would like to know about this event.
         """
diff --git a/synapse/handlers/appservice.py b/synapse/handlers/appservice.py
index 355ab317d..05735137d 100644
--- a/synapse/handlers/appservice.py
+++ b/synapse/handlers/appservice.py
@@ -147,10 +147,7 @@ class ApplicationServicesHandler(object):
                 )
             # We need to know the members associated with this event.room_id,
             # if any.
-            member_list = yield self.store.get_room_members(
-                room_id=event.room_id,
-                membership=Membership.JOIN
-            )
+            member_list = yield self.store.get_users_in_room(event.room_id)
 
         services = yield self.store.get_app_services()
         interested_list = [
diff --git a/tests/appservice/test_appservice.py b/tests/appservice/test_appservice.py
index 62149d690..8ce8dc0a8 100644
--- a/tests/appservice/test_appservice.py
+++ b/tests/appservice/test_appservice.py
@@ -217,18 +217,9 @@ class ApplicationServiceTestCase(unittest.TestCase):
             _regex("@irc_.*")
         )
         join_list = [
-            Mock(
-                type="m.room.member", room_id="!foo:bar", sender="@alice:here",
-                state_key="@alice:here"
-            ),
-            Mock(
-                type="m.room.member", room_id="!foo:bar", sender="@irc_fo:here",
-                state_key="@irc_fo:here"  # AS user
-            ),
-            Mock(
-                type="m.room.member", room_id="!foo:bar", sender="@bob:here",
-                state_key="@bob:here"
-            )
+            "@alice:here",
+            "@irc_fo:here",  # AS user
+            "@bob:here",
         ]
 
         self.event.sender = "@xmpp_foobar:matrix.org"