diff -r 8fba319750c2 -r 6ff6e1d6b5b8 mercurial/hgweb/hgweb_mod.py
--- a/mercurial/hgweb/hgweb_mod.py	Wed Feb 28 15:20:41 2018 -0500
+++ b/mercurial/hgweb/hgweb_mod.py	Thu Mar 08 23:10:46 2018 +0900
@@ -30,6 +30,7 @@
     repoview,
     templatefilters,
     templater,
+    templateutil,
     ui as uimod,
     util,
     wireprotoserver,
@@ -378,7 +379,7 @@
         try:
             rctx.tmpl = rctx.templater(req)
             ctype = rctx.tmpl('mimetype', encoding=encoding.encoding)
-            ctype = templater.stringify(ctype)
+            ctype = templateutil.stringify(ctype)
 
             # check read permissions non-static content
             if cmd != 'static':