diff --git a/hgext/largefiles/overrides.py b/hgext/largefiles/overrides.py
--- a/hgext/largefiles/overrides.py
+++ b/hgext/largefiles/overrides.py
@@ -812,9 +812,11 @@ def overridepull(orig, ui, repo, source=
         ui.status(_("%d largefiles cached\n") % numcached)
     return result
 
+revsetpredicate = revset.extpredicate()
+
+@revsetpredicate('pulled()')
 def pulledrevsetsymbol(repo, subset, x):
-    """``pulled()``
-    Changesets that just has been pulled.
+    """Changesets that just has been pulled.
 
     Only available with largefiles from pull --lfrev expressions.
 
diff --git a/hgext/largefiles/uisetup.py b/hgext/largefiles/uisetup.py
--- a/hgext/largefiles/uisetup.py
+++ b/hgext/largefiles/uisetup.py
@@ -9,7 +9,7 @@
 '''setup for largefiles extension: uisetup'''
 
 from mercurial import archival, cmdutil, commands, extensions, filemerge, hg, \
-    httppeer, merge, scmutil, sshpeer, wireproto, revset, subrepo, copies
+    httppeer, merge, scmutil, sshpeer, wireproto, subrepo, copies
 from mercurial.i18n import _
 from mercurial.hgweb import hgweb_mod, webcommands
 
@@ -83,7 +83,6 @@ def uisetup(ui):
                ('', 'lfrev', [],
                 _('download largefiles for these revisions'), _('REV'))]
     entry[1].extend(pullopt)
-    revset.symbols['pulled'] = overrides.pulledrevsetsymbol
 
     entry = extensions.wrapcommand(commands.table, 'clone',
                                    overrides.overrideclone)
@@ -170,3 +169,5 @@ def uisetup(ui):
         if name == 'transplant':
             extensions.wrapcommand(getattr(module, 'cmdtable'), 'transplant',
                 overrides.overridetransplant)
+
+    overrides.revsetpredicate.setup()
diff --git a/hgext/mq.py b/hgext/mq.py
--- a/hgext/mq.py
+++ b/hgext/mq.py
@@ -3558,9 +3558,11 @@ def summaryhook(ui, repo):
         # i18n: column positioning for "hg summary"
         ui.note(_("mq:     (empty queue)\n"))
 
+revsetpredicate = revset.extpredicate()
+
+@revsetpredicate('mq()')
 def revsetmq(repo, subset, x):
-    """``mq()``
-    Changesets managed by MQ.
+    """Changesets managed by MQ.
     """
     revset.getargs(x, 0, 0, _("mq takes no arguments"))
     applied = set([repo[r.node].rev() for r in repo.mq.applied])
@@ -3596,7 +3598,7 @@ def extsetup(ui):
         if extmodule.__file__ != __file__:
             dotable(getattr(extmodule, 'cmdtable', {}))
 
-    revset.symbols['mq'] = revsetmq
+    revsetpredicate.setup()
 
 colortable = {'qguard.negative': 'red',
               'qguard.positive': 'yellow',
diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -64,6 +64,9 @@ def _destrebase(repo):
     branch = repo[None].branch()
     return repo[branch].rev()
 
+revsetpredicate = revset.extpredicate()
+
+@revsetpredicate('_destrebase')
 def _revsetdestrebase(repo, subset, x):
     # ``_rebasedefaultdest()``
 
@@ -1238,4 +1241,4 @@ def uisetup(ui):
          _("use 'hg rebase --continue' or 'hg rebase --abort'")])
     # ensure rebased rev are not hidden
     extensions.wrapfunction(repoview, '_getdynamicblockers', _rebasedvisible)
-    revset.symbols['_destrebase'] = _revsetdestrebase
+    revsetpredicate.setup()
diff --git a/hgext/transplant.py b/hgext/transplant.py
--- a/hgext/transplant.py
+++ b/hgext/transplant.py
@@ -693,9 +693,11 @@ def _dotransplant(ui, repo, *revs, **opt
         if cleanupfn:
             cleanupfn()
 
+revsetpredicate = revset.extpredicate()
+
+@revsetpredicate('transplanted([set])')
 def revsettransplanted(repo, subset, x):
-    """``transplanted([set])``
-    Transplanted changesets in set, or all transplanted changesets.
+    """Transplanted changesets in set, or all transplanted changesets.
     """
     if x:
         s = revset.getset(repo, subset, x)
@@ -711,7 +713,7 @@ def kwtransplanted(repo, ctx, **args):
     return n and revlog.hex(n) or ''
 
 def extsetup(ui):
-    revset.symbols['transplanted'] = revsettransplanted
+    revsetpredicate.setup()
     templatekw.keywords['transplanted'] = kwtransplanted
     cmdutil.unfinishedstates.append(
         ['series', True, False, _('transplant in progress'),
diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -487,11 +487,36 @@ class predicate(registrar.funcregistrar)
 
     The first string argument of the constructor is used also in
     online help.
+
+    Use 'extpredicate' instead of this to register revset predicate in
+    extensions.
     """
     table = symbols
     formatdoc = "``%s``\n    %s"
     getname = registrar.funcregistrar.parsefuncdecl
 
+class extpredicate(registrar.delayregistrar):
+    """Decorator to register revset predicate in extensions
+
+    Usage::
+
+        revsetpredicate = revset.extpredicate()
+
+        @revsetpredicate('mypredicate(arg1, arg2[, arg3])')
+        def mypredicatefunc(repo, subset, x):
+            '''Explanation of this revset predicate ....
+            '''
+            pass
+
+        def uisetup(ui):
+            revsetpredicate.setup()
+
+    'revsetpredicate' instance above can be used to decorate multiple
+    functions, and 'setup()' on it registers all such functions at
+    once.
+    """
+    registrar = predicate
+
 @predicate('_destupdate')
 def _destupdate(repo, subset, x):
     # experimental revset for update destination
diff --git a/tests/test-revset.t b/tests/test-revset.t
--- a/tests/test-revset.t
+++ b/tests/test-revset.t
@@ -2189,3 +2189,43 @@ test error message of bad revset
   [255]
 
   $ cd ..
+
+Test registrar.delayregistrar via revset.extpredicate
+
+'extpredicate' decorator shouldn't register any functions until
+'setup()' on it.
+
+  $ cd repo
+
+  $ cat <<EOF > $TESTTMP/custompredicate.py
+  > from mercurial import revset
+  > 
+  > revsetpredicate = revset.extpredicate()
+  > 
+  > @revsetpredicate('custom1()')
+  > def custom1(repo, subset, x):
+  >     return revset.baseset([1])
+  > @revsetpredicate('custom2()')
+  > def custom2(repo, subset, x):
+  >     return revset.baseset([2])
+  > 
+  > def uisetup(ui):
+  >     if ui.configbool('custompredicate', 'enabled'):
+  >         revsetpredicate.setup()
+  > EOF
+  $ cat <<EOF > .hg/hgrc
+  > [extensions]
+  > custompredicate = $TESTTMP/custompredicate.py
+  > EOF
+
+  $ hg debugrevspec "custom1()"
+  hg: parse error: unknown identifier: custom1
+  [255]
+  $ hg debugrevspec "custom2()"
+  hg: parse error: unknown identifier: custom2
+  [255]
+  $ hg debugrevspec "custom1() or custom2()" --config custompredicate.enabled=true
+  1
+  2
+
+  $ cd ..