1 files changed, 22 insertions, 20 deletions
diff --git a/synapse/storage/databases/main/deviceinbox.py b/synapse/storage/databases/main/deviceinbox.py
index 744e98c6d0..1cf649d371 100644
--- a/synapse/storage/databases/main/deviceinbox.py
+++ b/synapse/storage/databases/main/deviceinbox.py
@@ -344,18 +344,19 @@ class DeviceInboxWorkerStore(SQLBaseStore):
             # Note that this is more efficient than just dropping `device_id` from the query,
             # since device_inbox has an index on `(user_id, device_id, stream_id)`
             if not device_ids_to_query:
-                user_device_dicts = self.db_pool.simple_select_many_txn(
-                    txn,
-                    table="devices",
-                    column="user_id",
-                    iterable=user_ids_to_query,
-                    keyvalues={"hidden": False},
-                    retcols=("device_id",),
+                user_device_dicts = cast(
+                    List[Tuple[str]],
+                    self.db_pool.simple_select_many_txn(
+                        txn,
+                        table="devices",
+                        column="user_id",
+                        iterable=user_ids_to_query,
+                        keyvalues={"hidden": False},
+                        retcols=("device_id",),
+                    ),
                 )
 
-                device_ids_to_query.update(
-                    {row["device_id"] for row in user_device_dicts}
-                )
+                device_ids_to_query.update({row[0] for row in user_device_dicts})
 
             if not device_ids_to_query:
                 # We've ended up with no devices to query.
@@ -845,20 +846,21 @@ class DeviceInboxWorkerStore(SQLBaseStore):
 
                 # We exclude hidden devices (such as cross-signing keys) here as they are
                 # not expected to receive to-device messages.
-                rows = self.db_pool.simple_select_many_txn(
-                    txn,
-                    table="devices",
-                    keyvalues={"user_id": user_id, "hidden": False},
-                    column="device_id",
-                    iterable=devices,
-                    retcols=("device_id",),
+                rows = cast(
+                    List[Tuple[str]],
+                    self.db_pool.simple_select_many_txn(
+                        txn,
+                        table="devices",
+                        keyvalues={"user_id": user_id, "hidden": False},
+                        column="device_id",
+                        iterable=devices,
+                        retcols=("device_id",),
+                    ),
                 )
 
-                for row in rows:
+                for (device_id,) in rows:
                     # Only insert into the local inbox if the device exists on
                     # this server
-                    device_id = row["device_id"]
-
                     with start_active_span("serialise_to_device_message"):
                         msg = messages_by_device[device_id]
                         set_tag(SynapseTags.TO_DEVICE_TYPE, msg["type"])