diff --git a/update_db.py b/update_db.py
index cdbf138..8a73c2d 100644
--- a/update_db.py
+++ b/update_db.py
@@ -59,7 +59,8 @@ def update_tables (
         video_tags = video.video_tags.where_not_null ('untagged_at').get ()
         for video_tag in video_tags:
             tag = video_tag.tag
-            if tag is not None and tag.name not in tag_names:
+            if (tag is not None
+                    and (tag.name.upper () not in map (str.upper, tag_names))):
                 video_tag.untagged_at = now
                 video_tag.save ()
         tags: list[Tag] = []