diff --git a/src/warc2zim/url_rewriting.py b/src/warc2zim/url_rewriting.py
index 96aaf36c..11de8ad9 100644
--- a/src/warc2zim/url_rewriting.py
+++ b/src/warc2zim/url_rewriting.py
@@ -126,9 +126,8 @@ def normalize(url: str | bytes) -> str:
     otherValue")
     "youtube.fuzzy.replayweb.page/youtubei/bar?videoId=xxxx"
     """
-
     if not url:
-        return url  # pyright: ignore
+        return ""
 
     url = to_string(url)