diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 63e633548d..a333acc4aa 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -832,7 +832,11 @@ class FederationHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def on_event_auth(self, event_id):
-        auth = yield self.store.get_auth_chain([event_id])
+        event = yield self.store.get_event(event_id)
+        auth = yield self.store.get_auth_chain(
+            [auth_id for auth_id, _ in event.auth_events],
+            include_given=True
+        )
 
         for event in auth:
             event.signatures.update(
@@ -1047,9 +1051,7 @@ class FederationHandler(BaseHandler):
                 yield user_joined_room(self.distributor, user, event.room_id)
 
         state_ids = context.prev_state_ids.values()
-        auth_chain = yield self.store.get_auth_chain(set(
-            [event.event_id] + state_ids
-        ))
+        auth_chain = yield self.store.get_auth_chain(state_ids)
 
         state = yield self.store.get_events(context.prev_state_ids.values())
 
@@ -1598,7 +1600,11 @@ class FederationHandler(BaseHandler):
                 pass
 
         # Now get the current auth_chain for the event.
-        local_auth_chain = yield self.store.get_auth_chain([event_id])
+        event = yield self.store.get_event(event_id)
+        local_auth_chain = yield self.store.get_auth_chain(
+            [auth_id for auth_id, _ in event.auth_events],
+            include_given=True
+        )
 
         # TODO: Check if we would now reject event_id. If so we need to tell
         # everyone.
@@ -1791,7 +1797,9 @@ class FederationHandler(BaseHandler):
                 auth_ids = yield self.auth.compute_auth_events(
                     event, context.prev_state_ids
                 )
-                local_auth_chain = yield self.store.get_auth_chain(auth_ids)
+                local_auth_chain = yield self.store.get_auth_chain(
+                    auth_ids, include_given=True
+                )
 
                 try:
                     # 2. Get remote difference.
diff --git a/synapse/storage/event_federation.py b/synapse/storage/event_federation.py
index 519059c306..72126c682e 100644
--- a/synapse/storage/event_federation.py
+++ b/synapse/storage/event_federation.py
@@ -44,18 +44,41 @@ class EventFederationStore(SQLBaseStore):
             self._delete_old_forward_extrem_cache, 60 * 60 * 1000
         )
 
-    def get_auth_chain(self, event_ids):
-        return self.get_auth_chain_ids(event_ids).addCallback(self._get_events)
+    def get_auth_chain(self, event_ids, include_given=False):
+        """Get auth events for given event_ids. The events *must* be state events.
 
-    def get_auth_chain_ids(self, event_ids):
+        Args:
+            event_ids (list): state events
+            include_given (bool): include the given events in result
+
+        Returns:
+            list of events
+        """
+        return self.get_auth_chain_ids(
+            event_ids, include_given=include_given,
+        ).addCallback(self._get_events)
+
+    def get_auth_chain_ids(self, event_ids, include_given=False):
+        """Get auth events for given event_ids. The events *must* be state events.
+
+        Args:
+            event_ids (list): state events
+            include_given (bool): include the given events in result
+
+        Returns:
+            list of event_ids
+        """
         return self.runInteraction(
             "get_auth_chain_ids",
             self._get_auth_chain_ids_txn,
-            event_ids
+            event_ids, include_given
         )
 
-    def _get_auth_chain_ids_txn(self, txn, event_ids):
-        results = set()
+    def _get_auth_chain_ids_txn(self, txn, event_ids, include_given):
+        if include_given:
+            results = set(event_ids)
+        else:
+            results = set()
 
         base_sql = (
             "SELECT auth_id FROM event_auth WHERE event_id IN (%s)"
diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index c4aeb48800..3d4f53ea55 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -1120,6 +1120,7 @@ class EventsStore(SQLBaseStore):
                 }
                 for event, _ in events_and_contexts
                 for auth_id, _ in event.auth_events
+                if event.is_state()
             ],
         )