diff --git a/hgext/amend.py b/hgext/amend.py
--- a/hgext/amend.py
+++ b/hgext/amend.py
@@ -36,6 +36,7 @@
      ('i', 'interactive', None, _('use interactive mode')),
      (b'', b'close-branch', None,
       _(b'mark a branch as closed, hiding it from the branch list')),
+     (b's', b'secret', None, _(b'use the secret phase for committing')),
      ('n', 'note', '', _('store a note on the amend')),
     ] + cmdutil.walkopts + cmdutil.commitopts + cmdutil.commitopts2
       + cmdutil.commitopts3,
diff --git a/relnotes/next b/relnotes/next
--- a/relnotes/next
+++ b/relnotes/next
@@ -4,6 +4,8 @@
 
  * The amend extension supports the `--close-branch` argument.
 
+ * The amend extension supports the `--secret` argument.
+
  * The uncommit extension supports the `rewrite.update-timestamp` config option.
 
 == New Experimental Features ==
diff --git a/tests/test-amend.t b/tests/test-amend.t
--- a/tests/test-amend.t
+++ b/tests/test-amend.t
@@ -452,9 +452,10 @@
 
 Close branch
 
-  $ hg amend --close-branch
-  $ hg log --limit 1 -T 'close={get(extras, "close")}\n'
+  $ hg amend --secret --close-branch
+  $ hg log --limit 1 -T 'close={get(extras, "close")}\nphase={phase}\n'
   close=1
+  phase=secret
 
   $ cd ..