diff --git a/hgext/uncommit.py b/hgext/uncommit.py
--- a/hgext/uncommit.py
+++ b/hgext/uncommit.py
@@ -111,7 +111,8 @@
 @command('uncommit',
     [('', 'keep', None, _('allow an empty commit after uncommiting')),
      ('', 'allow-dirty-working-copy', False,
-    _('allow uncommit with outstanding changes'))
+    _('allow uncommit with outstanding changes')),
+     (b'n', b'note', b'', _(b'store a note on uncommit'), _(b'TEXT'))
     ] + commands.walkopts + commands.commitopts + commands.commitopts2
     + commands.commitopts3,
     _('[OPTION]... [FILE]...'),
@@ -129,6 +130,7 @@
     """
     opts = pycompat.byteskwargs(opts)
 
+    cmdutil.checknotesize(ui, opts)
     cmdutil.resolvecommitoptions(ui, opts)
 
     with repo.wlock(), repo.lock():
diff --git a/tests/test-uncommit.t b/tests/test-uncommit.t
--- a/tests/test-uncommit.t
+++ b/tests/test-uncommit.t
@@ -36,6 +36,7 @@
   
       --keep                     allow an empty commit after uncommiting
       --allow-dirty-working-copy allow uncommit with outstanding changes
+   -n --note TEXT                store a note on uncommit
    -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
@@ -570,7 +571,7 @@
 
   $ hg rollback -q --config ui.rollback=True
   $ cd dir
-  $ hg uncommit .
+  $ hg uncommit . -n 'this is a note'
   note: keeping empty commit
   $ hg status
   A dir/file2.txt