diff --git a/backend/export.py b/backend/export.py
index 01eec00..c70bd0d 100644
--- a/backend/export.py
+++ b/backend/export.py
@@ -359,7 +359,7 @@ def export_epub(vault_path: Path, file_path: Path) -> bytes:
 
     rendered = _render_body(body, path.parent, vault_path, path)
 
-    uid = f"obsigate-{_slugify(title)}-{int(datetime.datetime.now(tz=datetime.timezone.utc).timestamp())}"
+    uid = f"obsigate-{_slugify(title)}-{int(datetime.datetime.now(tz=datetime.UTC).timestamp())}"
     xhtml = f"""<?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE html>
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="fr" lang="fr">
@@ -383,7 +383,7 @@ def export_epub(vault_path: Path, file_path: Path) -> bytes:
     <dc:title>{html_mod.escape(title)}</dc:title>
     <dc:creator>{html_mod.escape(author)}</dc:creator>
     <dc:language>fr</dc:language>
-    <meta property="dcterms:modified">{datetime.datetime.now(datetime.timezone.utc).strftime('%Y-%m-%dT%H:%M:%SZ')}</meta>
+    <meta property="dcterms:modified">{datetime.datetime.now(datetime.UTC).strftime('%Y-%m-%dT%H:%M:%SZ')}</meta>
   </metadata>
   <manifest>
     <item id="ncx" href="toc.ncx" media-type="application/x-dtbncx+xml"/>