diff --git a/workers/tagbackfillworker.py b/workers/tagbackfillworker.py
index e949b1dc1..42faddf0f 100644
--- a/workers/tagbackfillworker.py
+++ b/workers/tagbackfillworker.py
@@ -25,7 +25,7 @@ from util.migrate.allocator import yield_random_entries
 
 logger = logging.getLogger(__name__)
 
-WORKER_TIMEOUT = 600
+WORKER_TIMEOUT = 6000
 
 
 class BrokenManifest(ManifestInterface):
@@ -120,11 +120,7 @@ class TagBackfillWorker(Worker):
               .join(TagToRepositoryTag, JOIN.LEFT_OUTER)
               .where(TagToRepositoryTag.id >> None, RepositoryTag.hidden == False))
 
-    min_id = (RepositoryTag
-              .select(fn.Min(RepositoryTag.id))
-              .join(TagToRepositoryTag, JOIN.LEFT_OUTER)
-              .where(TagToRepositoryTag.id >> None, RepositoryTag.hidden == False)
-              .scalar())
+    min_id = (RepositoryTag.select(fn.Min(RepositoryTag.id)).scalar())
     max_id = RepositoryTag.select(fn.Max(RepositoryTag.id)).scalar()
 
     iterator = yield_random_entries(
@@ -227,7 +223,17 @@ def _get_manifest_id(repositorytag):
     return None
 
   try:
-    return TagManifestToManifest.get(tag_manifest=tag_manifest).manifest_id
+    found = TagManifestToManifest.get(tag_manifest=tag_manifest).manifest
+
+    # Verify that the new-style manifest has the same contents as the old-style manifest.
+    # If not, update and then return. This is an extra check put in place to ensure unicode
+    # manifests have been correctly copied.
+    if found.manifest_bytes != tag_manifest.json_data:
+      logger.warning('Fixing manifest `%s`', found.id)
+      found.manifest_bytes = tag_manifest.json_data
+      found.save()
+
+    return found.id
   except TagManifestToManifest.DoesNotExist:
     # Could not find the new style manifest, so backfill.
     _backfill_manifest(tag_manifest)