diff --git a/synapse/api/auth.py b/synapse/api/auth.py
index a342a0e0da..292e9e2a80 100644
--- a/synapse/api/auth.py
+++ b/synapse/api/auth.py
@@ -290,7 +290,9 @@ class Auth(object):
         Args:
             request - An HTTP request with an access_token query parameter.
         Returns:
-            UserID : User ID object of the user making the request
+            Tuple of UserID and device string:
+                User ID object of the user making the request
+                Device ID string of the device the user is using
         Raises:
             AuthError if no user by that token exists or the token is invalid.
         """
@@ -299,6 +301,7 @@ class Auth(object):
             access_token = request.args["access_token"][0]
             user_info = yield self.get_user_by_token(access_token)
             user = user_info["user"]
+            device_id = user_info["device_id"]
 
             ip_addr = self.hs.get_ip_from_request(request)
             user_agent = request.requestHeaders.getRawHeaders(
@@ -314,7 +317,7 @@ class Auth(object):
                     user_agent=user_agent
                 )
 
-            defer.returnValue(user)
+            defer.returnValue((user, device_id))
         except KeyError:
             raise AuthError(403, "Missing access token.")
 
diff --git a/synapse/rest/client/v1/admin.py b/synapse/rest/client/v1/admin.py
index 1051d96f96..6cfce1a479 100644
--- a/synapse/rest/client/v1/admin.py
+++ b/synapse/rest/client/v1/admin.py
@@ -31,7 +31,7 @@ class WhoisRestServlet(ClientV1RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, user_id):
         target_user = UserID.from_string(user_id)
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
         is_admin = yield self.auth.is_server_admin(auth_user)
 
         if not is_admin and target_user != auth_user:
diff --git a/synapse/rest/client/v1/directory.py b/synapse/rest/client/v1/directory.py
index 15ae8749b8..ef853af411 100644
--- a/synapse/rest/client/v1/directory.py
+++ b/synapse/rest/client/v1/directory.py
@@ -45,7 +45,7 @@ class ClientDirectoryServer(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_PUT(self, request, room_alias):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
 
         content = _parse_json(request)
         if not "room_id" in content:
@@ -85,7 +85,7 @@ class ClientDirectoryServer(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_DELETE(self, request, room_alias):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
 
         is_admin = yield self.auth.is_server_admin(user)
         if not is_admin:
diff --git a/synapse/rest/client/v1/events.py b/synapse/rest/client/v1/events.py
index a0d051227b..e58ee46fcd 100644
--- a/synapse/rest/client/v1/events.py
+++ b/synapse/rest/client/v1/events.py
@@ -34,7 +34,7 @@ class EventStreamRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
         try:
             handler = self.handlers.event_stream_handler
             pagin_config = PaginationConfig.from_request(request)
@@ -71,7 +71,7 @@ class EventRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, event_id):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
         handler = self.handlers.event_handler
         event = yield handler.get_event(auth_user, event_id)
 
diff --git a/synapse/rest/client/v1/initial_sync.py b/synapse/rest/client/v1/initial_sync.py
index 357fa845b4..78d30abbf8 100644
--- a/synapse/rest/client/v1/initial_sync.py
+++ b/synapse/rest/client/v1/initial_sync.py
@@ -25,7 +25,7 @@ class InitialSyncRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
         with_feedback = "feedback" in request.args
         as_client_event = "raw" not in request.args
         pagination_config = PaginationConfig.from_request(request)
diff --git a/synapse/rest/client/v1/presence.py b/synapse/rest/client/v1/presence.py
index b6c207e662..74669274a7 100644
--- a/synapse/rest/client/v1/presence.py
+++ b/synapse/rest/client/v1/presence.py
@@ -32,7 +32,7 @@ class PresenceStatusRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, user_id):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
         user = UserID.from_string(user_id)
 
         state = yield self.handlers.presence_handler.get_state(
@@ -42,7 +42,7 @@ class PresenceStatusRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_PUT(self, request, user_id):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
         user = UserID.from_string(user_id)
 
         state = {}
@@ -77,7 +77,7 @@ class PresenceListRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, user_id):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
         user = UserID.from_string(user_id)
 
         if not self.hs.is_mine(user):
@@ -97,7 +97,7 @@ class PresenceListRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_POST(self, request, user_id):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
         user = UserID.from_string(user_id)
 
         if not self.hs.is_mine(user):
diff --git a/synapse/rest/client/v1/profile.py b/synapse/rest/client/v1/profile.py
index 24f8d56952..f04abb2c26 100644
--- a/synapse/rest/client/v1/profile.py
+++ b/synapse/rest/client/v1/profile.py
@@ -37,7 +37,7 @@ class ProfileDisplaynameRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_PUT(self, request, user_id):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
         user = UserID.from_string(user_id)
 
         try:
@@ -70,7 +70,7 @@ class ProfileAvatarURLRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_PUT(self, request, user_id):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
         user = UserID.from_string(user_id)
 
         try:
diff --git a/synapse/rest/client/v1/room.py b/synapse/rest/client/v1/room.py
index 58b09b6fc1..c8c34b4801 100644
--- a/synapse/rest/client/v1/room.py
+++ b/synapse/rest/client/v1/room.py
@@ -62,7 +62,7 @@ class RoomCreateRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_POST(self, request):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
 
         room_config = self.get_room_config(request)
         info = yield self.make_room(room_config, auth_user, None)
@@ -125,7 +125,7 @@ class RoomStateEventRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, room_id, event_type, state_key):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
 
         msg_handler = self.handlers.message_handler
         data = yield msg_handler.get_room_data(
@@ -143,7 +143,7 @@ class RoomStateEventRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_PUT(self, request, room_id, event_type, state_key):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
 
         content = _parse_json(request)
 
@@ -173,7 +173,7 @@ class RoomSendEventRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_POST(self, request, room_id, event_type):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
         content = _parse_json(request)
 
         msg_handler = self.handlers.message_handler
@@ -216,7 +216,7 @@ class JoinRoomAliasServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_POST(self, request, room_identifier):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
 
         # the identifier could be a room alias or a room id. Try one then the
         # other if it fails to parse, without swallowing other valid
@@ -283,7 +283,7 @@ class RoomMemberListRestServlet(ClientV1RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, room_id):
         # TODO support Pagination stream API (limit/tokens)
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
         handler = self.handlers.room_member_handler
         members = yield handler.get_room_members_as_pagination_chunk(
             room_id=room_id,
@@ -311,7 +311,7 @@ class RoomMessageListRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, room_id):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
         pagination_config = PaginationConfig.from_request(
             request, default_limit=10,
         )
@@ -335,7 +335,7 @@ class RoomStateRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, room_id):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
         handler = self.handlers.message_handler
         # Get all the current state for this room
         events = yield handler.get_state_events(
@@ -351,7 +351,7 @@ class RoomInitialSyncRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, room_id):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
         pagination_config = PaginationConfig.from_request(request)
         content = yield self.handlers.message_handler.room_initial_sync(
             room_id=room_id,
@@ -396,7 +396,7 @@ class RoomMembershipRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_POST(self, request, room_id, membership_action):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
 
         content = _parse_json(request)
 
@@ -445,7 +445,7 @@ class RoomRedactEventRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_POST(self, request, room_id, event_id):
-        user = yield self.auth.get_user_by_req(request)
+        user, device_id = yield self.auth.get_user_by_req(request)
         content = _parse_json(request)
 
         msg_handler = self.handlers.message_handler
@@ -483,7 +483,7 @@ class RoomTypingRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_PUT(self, request, room_id, user_id):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
 
         room_id = urllib.unquote(room_id)
         target_user = UserID.from_string(urllib.unquote(user_id))
diff --git a/synapse/rest/client/v1/voip.py b/synapse/rest/client/v1/voip.py
index 822d863ce6..42d8e30bab 100644
--- a/synapse/rest/client/v1/voip.py
+++ b/synapse/rest/client/v1/voip.py
@@ -28,7 +28,7 @@ class VoipRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request):
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
 
         turnUris = self.hs.config.turn_uris
         turnSecret = self.hs.config.turn_shared_secret
diff --git a/synapse/rest/media/v0/content_repository.py b/synapse/rest/media/v0/content_repository.py
index 79ae0e3d74..311ab89edb 100644
--- a/synapse/rest/media/v0/content_repository.py
+++ b/synapse/rest/media/v0/content_repository.py
@@ -66,7 +66,7 @@ class ContentRepoResource(resource.Resource):
     @defer.inlineCallbacks
     def map_request_to_name(self, request):
         # auth the user
-        auth_user = yield self.auth.get_user_by_req(request)
+        auth_user, device_id = yield self.auth.get_user_by_req(request)
 
         # namespace all file uploads on the user
         prefix = base64.urlsafe_b64encode(
diff --git a/synapse/rest/media/v1/upload_resource.py b/synapse/rest/media/v1/upload_resource.py
index b1718a630b..6bed8a8efa 100644
--- a/synapse/rest/media/v1/upload_resource.py
+++ b/synapse/rest/media/v1/upload_resource.py
@@ -42,7 +42,7 @@ class UploadResource(BaseMediaResource):
     @defer.inlineCallbacks
     def _async_render_POST(self, request):
         try:
-            auth_user = yield self.auth.get_user_by_req(request)
+            auth_user, device_id = yield self.auth.get_user_by_req(request)
             # TODO: The checks here are a bit late. The content will have
             # already been uploaded to a tmp file at this point
             content_length = request.getHeader("Content-Length")
diff --git a/tests/rest/client/v1/test_presence.py b/tests/rest/client/v1/test_presence.py
index 65d5cc4916..a4f2abf213 100644
--- a/tests/rest/client/v1/test_presence.py
+++ b/tests/rest/client/v1/test_presence.py
@@ -282,7 +282,7 @@ class PresenceEventStreamTestCase(unittest.TestCase):
         hs.get_clock().time_msec.return_value = 1000000
 
         def _get_user_by_req(req=None):
-            return UserID.from_string(myid)
+            return (UserID.from_string(myid), "")
 
         hs.get_auth().get_user_by_req = _get_user_by_req
 
diff --git a/tests/rest/client/v1/test_profile.py b/tests/rest/client/v1/test_profile.py
index 39cd68d829..6a2085276a 100644
--- a/tests/rest/client/v1/test_profile.py
+++ b/tests/rest/client/v1/test_profile.py
@@ -58,7 +58,7 @@ class ProfileTestCase(unittest.TestCase):
         )
 
         def _get_user_by_req(request=None):
-            return UserID.from_string(myid)
+            return (UserID.from_string(myid), "")
 
         hs.get_auth().get_user_by_req = _get_user_by_req