diff --git a/mercurial/archival.py b/mercurial/archival.py
--- a/mercurial/archival.py
+++ b/mercurial/archival.py
@@ -136,39 +136,6 @@
     """write archive to tar file or stream.  can write uncompressed,
     or compress with gzip or bzip2."""
 
-    if pycompat.ispy3:
-        GzipFileWithTime = gzip.GzipFile  # camelcase-required
-    else:
-
-        class GzipFileWithTime(gzip.GzipFile):
-            def __init__(self, *args, **kw):
-                timestamp = None
-                if 'mtime' in kw:
-                    timestamp = kw.pop('mtime')
-                if timestamp is None:
-                    self.timestamp = time.time()
-                else:
-                    self.timestamp = timestamp
-                gzip.GzipFile.__init__(self, *args, **kw)
-
-            def _write_gzip_header(self):
-                self.fileobj.write(b'\037\213')  # magic header
-                self.fileobj.write(b'\010')  # compression method
-                fname = self.name
-                if fname and fname.endswith(b'.gz'):
-                    fname = fname[:-3]
-                flags = 0
-                if fname:
-                    flags = gzip.FNAME  # pytype: disable=module-attr
-                self.fileobj.write(pycompat.bytechr(flags))
-                gzip.write32u(  # pytype: disable=module-attr
-                    self.fileobj, int(self.timestamp)
-                )
-                self.fileobj.write(b'\002')
-                self.fileobj.write(b'\377')
-                if fname:
-                    self.fileobj.write(fname + b'\000')
-
     def __init__(self, dest, mtime, kind=b''):
         self.mtime = mtime
         self.fileobj = None
@@ -178,7 +145,7 @@
                 mode = mode[0:1]
                 if not fileobj:
                     fileobj = open(name, mode + b'b')
-                gzfileobj = self.GzipFileWithTime(
+                gzfileobj = gzip.GzipFile(
                     name,
                     pycompat.sysstr(mode + b'b'),
                     zlib.Z_BEST_COMPRESSION,