diff --git a/synapse/storage/devices.py b/synapse/storage/devices.py
index 046c000c40..3b2e9c6699 100644
--- a/synapse/storage/devices.py
+++ b/synapse/storage/devices.py
@@ -194,8 +194,8 @@ class DeviceWorkerStore(SQLBaseStore):
         Args:
             destination (str): The host the device updates are intended for
             from_stream_id (int): The minimum stream_id to filter updates by, exclusive
-            query_map (Dict[(str, str): int]): Dictionary mapping
-                user_id/device_id to update stream_id
+            query_map (Dict[(str, str): (int, str)]): Dictionary mapping
+                user_id/device_id to update stream_id and the relevent opentracing context
 
         Returns:
             List[Dict]: List of objects representing an device update EDU
@@ -217,7 +217,7 @@ class DeviceWorkerStore(SQLBaseStore):
                 destination, user_id, from_stream_id
             )
             for device_id, device in iteritems(user_devices):
-                stream_id = query_map[(user_id, device_id)][0]
+                stream_id, _ = query_map[(user_id, device_id)]
                 result = {
                     "user_id": user_id,
                     "device_id": device_id,