--- a/hgext/patchbomb.py	Tue Nov 12 22:52:30 2019 +0100
+++ b/hgext/patchbomb.py	Wed Nov 13 15:23:04 2019 +0100
@@ -285,7 +285,7 @@
         if body:
             msg.attach(mail.mimeencode(ui, body, _charsets, opts.get(b'test')))
         p = mail.mimetextpatch(
-            b'\n'.join(patchlines), b'x-patch', opts.get(b'test')
+            b'\n'.join(patchlines), 'x-patch', opts.get(b'test')
         )
         binnode = nodemod.bin(node)
         # if node is mq patch, it will have the patch file's name as a tag