diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -5524,7 +5524,11 @@
 
         # if we defined a bookmark, we have to remember the original name
         brev = rev
-        rev = scmutil.revsingle(repo, rev, rev).rev()
+        repo = scmutil.unhidehashlikerevs(repo, [rev], 'nowarn')
+        ctx = scmutil.revsingle(repo, rev, rev)
+        rev = ctx.rev()
+        if repo.filtername == 'visible-hidden':
+            ui.warn(_("updating to a hidden changeset %s\n") % ctx.hex()[:12])
 
         repo.ui.setconfig('ui', 'forcemerge', tool, 'update')
 
diff --git a/tests/test-directaccess.t b/tests/test-directaccess.t
--- a/tests/test-directaccess.t
+++ b/tests/test-directaccess.t
@@ -143,6 +143,15 @@
   $ hg status --change 28ad74
   A c
 
+`hg update`
+
+  $ hg up 28ad74
+  updating to a hidden changeset 28ad74487de9
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+
+  $ hg up 3
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+
 Commands with undefined cmdtype should not work right now
 
   $ hg phase -r 28ad74