diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 90649af9e1..2bfd0a40e0 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -229,7 +229,7 @@ class FederationHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def _filter_events_for_server(self, server_name, room_id, events):
-        states = yield self.store.get_state_for_events(
+        event_to_state = yield self.store.get_state_for_events(
             room_id, frozenset(e.event_id for e in events),
             types=(
                 (EventTypes.RoomHistoryVisibility, ""),
@@ -237,8 +237,6 @@ class FederationHandler(BaseHandler):
             )
         )
 
-        events_and_states = zip(events, states)
-
         def redact_disallowed(event_and_state):
             event, state = event_and_state
 
@@ -275,9 +273,10 @@ class FederationHandler(BaseHandler):
 
             return event
 
-        res = map(redact_disallowed, events_and_states)
-
-        logger.info("_filter_events_for_server %r", res)
+        res = map(redact_disallowed, [
+            (e, event_to_state[e.event_id])
+            for e in events
+        ])
 
         defer.returnValue(res)
 
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 11c736f727..95a8f05c05 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -137,7 +137,7 @@ class MessageHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def _filter_events_for_client(self, user_id, room_id, events):
-        states = yield self.store.get_state_for_events(
+        event_id_to_state = yield self.store.get_state_for_events(
             room_id, frozenset(e.event_id for e in events),
             types=(
                 (EventTypes.RoomHistoryVisibility, ""),
@@ -145,7 +145,8 @@ class MessageHandler(BaseHandler):
             )
         )
 
-        events_and_states = zip(events, states)
+        for ev, state in event_id_to_state.items():
+            logger.info("event_id: %r, state: %r", ev, state)
 
         def allowed(event_and_state):
             event, state = event_and_state
@@ -179,10 +180,17 @@ class MessageHandler(BaseHandler):
 
             return True
 
-        events_and_states = filter(allowed, events_and_states)
+        event_and_state = filter(
+            allowed,
+            [
+                (e, event_id_to_state[e.event_id])
+                for e in events
+            ]
+        )
+
         defer.returnValue([
             ev
-            for ev, _ in events_and_states
+            for ev, _ in event_and_state
         ])
 
     @defer.inlineCallbacks
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 8f58774b31..9a97bff840 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -294,7 +294,7 @@ class SyncHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def _filter_events_for_client(self, user_id, room_id, events):
-        states = yield self.store.get_state_for_events(
+        event_id_to_state = yield self.store.get_state_for_events(
             room_id, frozenset(e.event_id for e in events),
             types=(
                 (EventTypes.RoomHistoryVisibility, ""),
@@ -302,7 +302,8 @@ class SyncHandler(BaseHandler):
             )
         )
 
-        events_and_states = zip(events, states)
+        for ev, state in event_id_to_state.items():
+            logger.info("event_id: %r, state: %r", ev, state)
 
         def allowed(event_and_state):
             event, state = event_and_state
@@ -335,10 +336,18 @@ class SyncHandler(BaseHandler):
                 return membership == Membership.INVITE
 
             return True
-        events_and_states = filter(allowed, events_and_states)
+
+        event_and_state = filter(
+            allowed,
+            [
+                (e, event_id_to_state[e.event_id])
+                for e in events
+            ]
+        )
+
         defer.returnValue([
             ev
-            for ev, _ in events_and_states
+            for ev, _ in event_and_state
         ])
 
     @defer.inlineCallbacks
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 19b16ed404..a438530071 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -239,10 +239,10 @@ class StateStore(SQLBaseStore):
             for event_id, group in event_to_groups.items()
         }
 
-        defer.returnValue([
-            event_to_state[event]
+        defer.returnValue({
+            event: event_to_state[event]
             for event in event_ids
-        ])
+        })
 
     @cached(num_args=2, lru=True, max_entries=100000)
     def _get_state_group_for_event(self, room_id, event_id):