diff --git a/tests/test-clone-uncompressed.t b/tests/test-clone-uncompressed.t
--- a/tests/test-clone-uncompressed.t
+++ b/tests/test-clone-uncompressed.t
@@ -18,7 +18,7 @@
   $ hg -q commit -A -m initial
   >>> for i in range(1024):
   ...     with open(str(i), 'wb') as fh:
-  ...         fh.write(str(i))
+  ...         fh.write(b"%d" % i) and None
   $ hg -q commit -A -m 'add a lot of files'
   $ hg st
   $ hg --config server.uncompressed=false serve -p $HGPORT -d --pid-file=hg.pid