diff --git a/mercurial/hgweb/webutil.py b/mercurial/hgweb/webutil.py
--- a/mercurial/hgweb/webutil.py
+++ b/mercurial/hgweb/webutil.py
@@ -791,7 +791,7 @@
         flagin = match.group(3)
         flags = 0
         if flagin:
-            for flag in flagin.upper():
+            for flag in pycompat.sysstr(flagin.upper()):
                 flags |= re.__dict__[flag]
 
         try:
diff --git a/tests/test-websub.t b/tests/test-websub.t
--- a/tests/test-websub.t
+++ b/tests/test-websub.t
@@ -11,16 +11,18 @@
   > 
   > [websub]
   > issues = s|Issue(\d+)|<a href="http://bts.example.org/issue\1">Issue\1</a>|
+  > tickets = s|ticket(\d+)|<a href="http://ticket.example.org/issue\1">Ticket\1</a>|i
   > 
   > [interhg]
   > # check that we maintain some interhg backwards compatibility...
   > # yes, 'x' is a weird delimiter...
   > markbugs = sxbugx<i class="\x">bug</i>x
+  > problems = sxPROBLEMx<i class="\x">problem</i>xi
   > EOF
 
   $ touch foo
   $ hg add foo
-  $ hg commit -d '1 0' -m 'Issue123: fixed the bug!'
+  $ hg commit -d '1 0' -m 'Issue123: fixed the bug! Ticket456 and problem789 too'
 
   $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
   $ cat hg.pid >> $DAEMON_PIDS
@@ -28,7 +30,7 @@
 log
 
   $ get-with-headers.py localhost:$HGPORT "rev/tip" | grep bts
-  <div class="description"><a href="http://bts.example.org/issue123">Issue123</a>: fixed the <i class="x">bug</i>!</div>
+  <div class="description"><a href="http://bts.example.org/issue123">Issue123</a>: fixed the <i class="x">bug</i>! <a href="http://ticket.example.org/issue456">Ticket456</a> and <i class="x">problem</i>789 too</div>
 errors
 
   $ cat errors.log