diff --git a/mercurial/hgweb/request.py b/mercurial/hgweb/request.py
--- a/mercurial/hgweb/request.py
+++ b/mercurial/hgweb/request.py
@@ -59,7 +59,7 @@ class _wsgirequest(object):
     def write(self, *things):
         if self.server_write is None:
             if not self.headers:
-                raise RuntimeError("request.write called before headers sent.")
+                self.header()
             self.server_write = self.start_response('200 Script output follows',
                                                     self.headers)
             self.start_response = None
diff --git a/mercurial/hgweb/server.py b/mercurial/hgweb/server.py
--- a/mercurial/hgweb/server.py
+++ b/mercurial/hgweb/server.py
@@ -196,7 +196,7 @@ def create_server(ui, repo):
         def __init__(self, *args, **kwargs):
             if self.address_family is None:
                 raise hg.RepoError(_('IPv6 not available on this system'))
-            super(IPv6HTTPServer, self).__init__(*args, **kargs)
+            super(IPv6HTTPServer, self).__init__(*args, **kwargs)
 
     if use_ipv6:
         return IPv6HTTPServer((address, port), _hgwebhandler)