diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1583,6 +1583,7 @@
     ('', 'amend', None, _('amend the parent of the working directory')),
     ('s', 'secret', None, _('use the secret phase for committing')),
     ('e', 'edit', None, _('invoke editor on commit messages')),
+    ('f', 'force', None, _('forcibly close branch from a non-head changeset')),
     ('i', 'interactive', None, _('use interactive mode')),
     ] + walkopts + commitopts + commitopts2 + subrepoopts,
     _('[OPTION]... [FILE]...'),
@@ -1675,12 +1676,18 @@
 
         if not bheads:
             raise error.Abort(_('can only close branch heads'))
-        elif branch == repo['.'].branch() and repo['.'].node() not in bheads:
-            raise error.Abort(_('can only close branch heads'))
+        elif (branch == repo['.'].branch() and repo['.'].node() not in bheads
+              and not opts.get('force')):
+            hint = _("use --force to close a non-head changeset")
+            raise error.Abort(_('can only close branch heads'), hint=hint)
         elif opts.get('amend'):
             if (repo['.'].p1().branch() != branch and
                 repo['.'].p2().branch() != branch):
                 raise error.Abort(_('can only close branch heads'))
+    if opts.get('force'):
+        # remove 'force' from opts as it can bypass some internal commit
+        # functions.
+        del opts['force']
 
     if opts.get('amend'):
         if ui.configbool('ui', 'commitsubrepos'):
diff --git a/tests/test-alias.t b/tests/test-alias.t
--- a/tests/test-alias.t
+++ b/tests/test-alias.t
@@ -120,6 +120,7 @@
       --amend               amend the parent of the working directory
    -s --secret              use the secret phase for committing
    -e --edit                invoke editor on commit messages
+   -f --force               forcibly close branch from a non-head changeset
    -i --interactive         use interactive mode
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
diff --git a/tests/test-branches.t b/tests/test-branches.t
--- a/tests/test-branches.t
+++ b/tests/test-branches.t
@@ -958,6 +958,7 @@
 it should abort:
   $ hg ci -m "closing branch" --close-branch
   abort: can only close branch heads
+  (use --force to close a non-head changeset)
   [255]
 
   $ hg up 0
@@ -972,3 +973,19 @@
   @  0: 9092f1db7931 added a
      	default
   
+Check --force to close a branch from a cset which is not a branch head
+
+  $ hg show stack --config extensions.show=
+    o  1553 added c
+    o  5f6d added b
+    @  9092 added a
+
+without --force
+  $ hg ci -m "branch closed" --close-branch
+  abort: can only close branch heads
+  (use --force to close a non-head changeset)
+  [255]
+
+with --force
+  $ hg ci -m "branch closed" --close-branch --force
+  created new head
diff --git a/tests/test-completion.t b/tests/test-completion.t
--- a/tests/test-completion.t
+++ b/tests/test-completion.t
@@ -245,7 +245,7 @@
   bundle: force, rev, branch, base, all, type, ssh, remotecmd, insecure
   cat: output, rev, decode, include, exclude, template
   clone: noupdate, updaterev, rev, branch, pull, uncompressed, stream, ssh, remotecmd, insecure
-  commit: addremove, close-branch, amend, secret, edit, interactive, include, exclude, message, logfile, date, user, subrepos
+  commit: addremove, close-branch, amend, secret, edit, force, interactive, include, exclude, message, logfile, date, user, subrepos
   config: untrusted, edit, local, global, template
   copy: after, force, include, exclude, dry-run
   debugancestor: 
diff --git a/tests/test-qrecord.t b/tests/test-qrecord.t
--- a/tests/test-qrecord.t
+++ b/tests/test-qrecord.t
@@ -69,6 +69,7 @@
       --amend               amend the parent of the working directory
    -s --secret              use the secret phase for committing
    -e --edit                invoke editor on commit messages
+   -f --force               forcibly close branch from a non-head changeset
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -m --message TEXT        use text as commit message
diff --git a/tests/test-record.t b/tests/test-record.t
--- a/tests/test-record.t
+++ b/tests/test-record.t
@@ -52,6 +52,7 @@
       --amend               amend the parent of the working directory
    -s --secret              use the secret phase for committing
    -e --edit                invoke editor on commit messages
+   -f --force               forcibly close branch from a non-head changeset
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -m --message TEXT        use text as commit message