diff --git a/changelog.d/19947.bugfix b/changelog.d/19947.bugfix
new file mode 100644
index 0000000000..c16d6deea0
--- /dev/null
+++ b/changelog.d/19947.bugfix
@@ -0,0 +1 @@
+Fix a bug causing device list pruning to skip some rows when the transaction gets retried.
\ No newline at end of file
diff --git a/synapse/storage/databases/main/devices.py b/synapse/storage/databases/main/devices.py
index b293b47fea..0e4c8ac491 100644
--- a/synapse/storage/databases/main/devices.py
+++ b/synapse/storage/databases/main/devices.py
@@ -2561,9 +2561,14 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
         # We default to 0 here as that is less than all possible stream IDs.
         min_stream_id = 0
 
-        def prune_device_lists_changes_in_room_txn(txn: LoggingTransaction) -> int:
-            nonlocal min_stream_id
-
+        def prune_device_lists_changes_in_room_txn(
+            txn: LoggingTransaction, min_stream_id: int
+        ) -> tuple[int, int]:
+            """
+            Returns tuple of:
+                - number of rows deleted
+                - new `min_stream_id` for the next iteration
+            """
             delete_sql = """
                 DELETE FROM device_lists_changes_in_room
                 WHERE stream_id IN (
@@ -2596,13 +2601,14 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
                     updatevalues={"stream_id": min_stream_id},
                 )
 
-            return num_deleted
+            return num_deleted, min_stream_id
 
         progress_num_rows_deleted = 0
         while True:
-            batch_deleted = await self.db_pool.runInteraction(
+            batch_deleted, min_stream_id = await self.db_pool.runInteraction(
                 "prune_device_lists_changes_in_room",
                 prune_device_lists_changes_in_room_txn,
+                min_stream_id,
             )
 
             finished = batch_deleted < PRUNE_DEVICE_LISTS_BATCH_SIZE