diff --git a/mercurial/archival.py b/mercurial/archival.py
--- a/mercurial/archival.py
+++ b/mercurial/archival.py
@@ -203,7 +203,9 @@
     or compressed with deflate.'''
 
     def __init__(self, dest, mtime, compress=True):
-        self.z = zipfile.ZipFile(pycompat.fsdecode(dest), r'w',
+        if isinstance(dest, bytes):
+            dest = pycompat.fsdecode(dest)
+        self.z = zipfile.ZipFile(dest, r'w',
                                  compress and zipfile.ZIP_DEFLATED or
                                  zipfile.ZIP_STORED)