1 files changed, 7 insertions, 12 deletions
diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py
index f43463df53..56818f4df8 100644
--- a/synapse/storage/background_updates.py
+++ b/synapse/storage/background_updates.py
@@ -16,11 +16,8 @@
 import logging
 from typing import Optional
 
-from canonicaljson import json
-
-from twisted.internet import defer
-
 from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.util import json_encoder
 
 from . import engines
 
@@ -308,9 +305,8 @@ class BackgroundUpdater(object):
             update_name (str): Name of update
         """
 
-        @defer.inlineCallbacks
-        def noop_update(progress, batch_size):
-            yield self._end_background_update(update_name)
+        async def noop_update(progress, batch_size):
+            await self._end_background_update(update_name)
             return 1
 
         self.register_background_update_handler(update_name, noop_update)
@@ -409,12 +405,11 @@ class BackgroundUpdater(object):
         else:
             runner = create_index_sqlite
 
-        @defer.inlineCallbacks
-        def updater(progress, batch_size):
+        async def updater(progress, batch_size):
             if runner is not None:
                 logger.info("Adding index %s to %s", index_name, table)
-                yield self.db_pool.runWithConnection(runner)
-            yield self._end_background_update(update_name)
+                await self.db_pool.runWithConnection(runner)
+            await self._end_background_update(update_name)
             return 1
 
         self.register_background_update_handler(update_name, updater)
@@ -461,7 +456,7 @@ class BackgroundUpdater(object):
             progress(dict): The progress of the update.
         """
 
-        progress_json = json.dumps(progress)
+        progress_json = json_encoder.encode(progress)
 
         self.db_pool.simple_update_one_txn(
             txn,