diff --git a/app.py b/app.py
index aeef0ef55..d31c49397 100644
--- a/app.py
+++ b/app.py
@@ -106,9 +106,6 @@ class InjectingFilter(logging.Filter):
 
 root_logger = logging.getLogger()
 
-# Add a null handler to the root logger to silence missing handler errors in tests
-root_logger.addHandler(logging.NullHandler())
-
 # Add the request id filter to all handlers of the root logger
 for handler in root_logger.handlers:
   handler.addFilter(InjectingFilter())
diff --git a/util/migrate/allocator.py b/util/migrate/allocator.py
index b25ed3cf7..c0502a843 100644
--- a/util/migrate/allocator.py
+++ b/util/migrate/allocator.py
@@ -132,13 +132,15 @@ def yield_random_entries(batch_query, primary_key_field, batch_size, max_id):
   try:
     while True:
       start_index = allocator.get_block_start_index(batch_size)
+      end_index = min(start_index + batch_size, max_id + 1)
       all_candidates = list(batch_query()
                             .where(primary_key_field >= start_index,
-                                   primary_key_field <= start_index + batch_size))
+                                   primary_key_field < end_index)
+                            .order_by(primary_key_field))
 
       if len(all_candidates) == 0:
-        logger.info('No candidates, new highest id: %s', start_index)
-        allocator.mark_completed(start_index, max_id + 1)
+        logger.info('No candidates, marking entire block completed %s-%s', start_index, end_index)
+        allocator.mark_completed(start_index, end_index)
         continue
 
       logger.info('Found %s candidates, processing block', len(all_candidates))
diff --git a/util/migrate/backfill_content_checksums_and_torrent_pieces.py b/util/migrate/backfill_content_checksums_and_torrent_pieces.py
index 4a13f2e64..c20b96bad 100644
--- a/util/migrate/backfill_content_checksums_and_torrent_pieces.py
+++ b/util/migrate/backfill_content_checksums_and_torrent_pieces.py
@@ -88,7 +88,7 @@ def backfill_content_checksums_and_torrent_pieces(piece_length):
                                                        max_id):
     locations = _get_image_storage_locations(candidate_storage.id)
 
-    checksum = ImageStorage.content_checksum
+    checksum = candidate_storage.content_checksum
     torrent_pieces = ''
     with CloseForLongOperation(app.config):
       try: