diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -1765,6 +1765,20 @@ def rev(repo, subset, x):
         return baseset()
     return subset & baseset([l])
 
+@predicate('_rev(number)', safe=True)
+def _rev(repo, subset, x):
+    # internal version of "rev(x)" that raise error if "x" is invalid
+    # i18n: "rev" is a keyword
+    l = getargs(x, 1, 1, _("rev requires one argument"))
+    try:
+        # i18n: "rev" is a keyword
+        l = int(getstring(l[0], _("rev requires a number")))
+    except (TypeError, ValueError):
+        # i18n: "rev" is a keyword
+        raise error.ParseError(_("rev expects a number"))
+    repo.changelog.node(l) # check that the rev exists
+    return subset & baseset([l])
+
 @predicate('revset(set)', safe=True, takeorder=True)
 def revsetpredicate(repo, subset, x, order):
     """Strictly interpret the content as a revset.
diff --git a/mercurial/revsetlang.py b/mercurial/revsetlang.py
--- a/mercurial/revsetlang.py
+++ b/mercurial/revsetlang.py
@@ -585,7 +585,7 @@ def _quote(s):
 
 def _formatargtype(c, arg):
     if c == 'd':
-        return 'rev(%d)' % int(arg)
+        return '_rev(%d)' % int(arg)
     elif c == 's':
         return _quote(arg)
     elif c == 'r':
@@ -663,9 +663,9 @@ def formatspec(expr, *args):
     >>> formatspec(b'%r:: and %lr', b'10 or 11', (b"this()", b"that()"))
     '(10 or 11):: and ((this()) or (that()))'
     >>> formatspec(b'%d:: and not %d::', 10, 20)
-    'rev(10):: and not rev(20)::'
+    '_rev(10):: and not _rev(20)::'
     >>> formatspec(b'%ld or %ld', [], [1])
-    "_list('') or rev(1)"
+    "_list('') or _rev(1)"
     >>> formatspec(b'keyword(%s)', b'foo\\xe9')
     "keyword('foo\\\\xe9')"
     >>> b = lambda: b'default'