3 files changed, 4 insertions, 4 deletions
diff --git a/synapse/state/__init__.py b/synapse/state/__init__.py
index c981df3f18..5cf2e12575 100644
--- a/synapse/state/__init__.py
+++ b/synapse/state/__init__.py
@@ -118,7 +118,7 @@ class _StateCacheEntry:
         else:
             self.state_id = _gen_state_id()
 
-    def __len__(self):
+    def __len__(self) -> int:
         return len(self.state)
 
 
diff --git a/synapse/state/v1.py b/synapse/state/v1.py
index 017e6fd92d..ffe6207a3c 100644
--- a/synapse/state/v1.py
+++ b/synapse/state/v1.py
@@ -225,7 +225,7 @@ def _resolve_with_state(
     conflicted_state_ids: StateMap[Set[str]],
     auth_event_ids: StateMap[str],
     state_map: Dict[str, EventBase],
-):
+) -> MutableStateMap[str]:
     conflicted_state = {}
     for key, event_ids in conflicted_state_ids.items():
         events = [state_map[ev_id] for ev_id in event_ids if ev_id in state_map]
@@ -362,7 +362,7 @@ def _resolve_normal_events(
 
 
 def _ordered_events(events: Iterable[EventBase]) -> List[EventBase]:
-    def key_func(e):
+    def key_func(e: EventBase) -> Tuple[int, str]:
         # we have to use utf-8 rather than ascii here because it turns out we allow
         # people to send us events with non-ascii event IDs :/
         return -int(e.depth), hashlib.sha1(e.event_id.encode("utf-8")).hexdigest()
diff --git a/synapse/state/v2.py b/synapse/state/v2.py
index 586b0e12fe..bd18eefd58 100644
--- a/synapse/state/v2.py
+++ b/synapse/state/v2.py
@@ -481,7 +481,7 @@ async def _reverse_topological_power_sort(
         if idx % _AWAIT_AFTER_ITERATIONS == 0:
             await clock.sleep(0)
 
-    def _get_power_order(event_id):
+    def _get_power_order(event_id: str) -> Tuple[int, int, str]:
         ev = event_map[event_id]
         pl = event_to_pl[event_id]