diff -r 3e6b36ba16ac -r f12de15c5711 mercurial/hgweb/webcommands.py
--- a/mercurial/hgweb/webcommands.py	Wed Oct 11 04:15:08 2017 +0200
+++ b/mercurial/hgweb/webcommands.py	Wed Oct 11 04:15:24 2017 +0200
@@ -93,7 +93,7 @@
 
 @webcommand('rawfile')
 def rawfile(web, req, tmpl):
-    guessmime = web.configbool('web', 'guessmime', False)
+    guessmime = web.configbool('web', 'guessmime')
 
     path = webutil.cleanpath(web.repo, req.form.get('file', [''])[0])
     if not path: