2 files changed, 3 insertions, 5 deletions
diff --git a/synapse/handlers/_base.py b/synapse/handlers/_base.py
index 833ff41377..d6c064b398 100644
--- a/synapse/handlers/_base.py
+++ b/synapse/handlers/_base.py
@@ -78,7 +78,9 @@ class BaseHandler(object):
         context = yield state_handler.compute_event_context(builder)
 
         if builder.is_state():
-            builder.prev_state = context.prev_state_events
+            builder.prev_state = yield self.store.add_event_hashes(
+                context.prev_state_events
+            )
 
         yield self.auth.add_auth_events(builder, context)
 
diff --git a/synapse/state.py b/synapse/state.py
index 8a635f1cc1..80da90a72c 100644
--- a/synapse/state.py
+++ b/synapse/state.py
@@ -169,10 +169,6 @@ class StateHandler(object):
         context.current_state = curr_state
         context.state_group = group if not event.is_state() else None
 
-        prev_state = yield self.store.add_event_hashes(
-            prev_state
-        )
-
         if event.is_state():
             key = (event.type, event.state_key)
             if key in context.current_state: