diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 187ad57033..e189989408 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -110,6 +110,7 @@ class FederationHandler(BaseHandler):
 
         self.hs = hs
 
+        self.clock = hs.get_clock()
         self.store = hs.get_datastore()  # type: synapse.storage.DataStore
         self.federation_client = hs.get_federation_client()
         self.federation_sender = hs.get_federation_sender()
@@ -1435,7 +1436,7 @@ class FederationHandler(BaseHandler):
             except Exception:
                 # We're going to retry, but we should log the error
                 logger.exception("Error auto-accepting invite on attempt %d" % attempt)
-                yield self.hs.get_clock().sleep(1)
+                yield self.clock.sleep(1)
         if not joined:
             logger.error("Giving up on trying to auto-accept invite: too many attempts")
 
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 18342fb675..147f8e1789 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -455,10 +455,11 @@ class RoomMemberHandler(object):
             prev_events_and_hashes=prev_events_and_hashes,
             content=content,
         )
-        logcontext.run_in_background(
-            self._send_merged_user_invites,
-            requester, room_id,
-        )
+        if effective_membership_state == Membership.JOIN:
+            logcontext.run_in_background(
+                self._send_merged_user_invites,
+                requester, room_id,
+            )
         defer.returnValue(res)
 
     @defer.inlineCallbacks
@@ -479,12 +480,15 @@ class RoomMemberHandler(object):
                 if self.hs.is_mine(child) or child_id == requester.user.to_string():
                     # TODO: Handle auto-invite for local users (not a priority)
                     continue
-                self.update_membership(
-                    requester=requester,
-                    target=child,
-                    room_id=room_id,
-                    action="invite",
-                )
+                try:
+                    yield self.update_membership(
+                        requester=requester,
+                        target=child,
+                        room_id=room_id,
+                        action="invite",
+                    )
+                except Exception:
+                    logger.exception("Failed to invite %s to %s" % (child_id, room_id))
 
     @defer.inlineCallbacks
     def send_membership_event(