diff --git a/mercurial/fancyopts.py b/mercurial/fancyopts.py
--- a/mercurial/fancyopts.py
+++ b/mercurial/fancyopts.py
@@ -11,7 +11,8 @@ def fancyopts(args, options, state):
         map['-'+s] = map['--'+l] = pl
         state[pl] = d
         dt[pl] = type(d)
-        if not d is None and not callable(d):
+        if (d is not None and d is not True and d is not False and
+            not callable(d)):
             if s: s += ':'
             if l: l += '='
         if s: short = short + s
@@ -25,6 +26,7 @@ def fancyopts(args, options, state):
         elif dt[map[opt]] is type(''): state[map[opt]] = arg
         elif dt[map[opt]] is type([]): state[map[opt]].append(arg)
         elif dt[map[opt]] is type(None): state[map[opt]] = True
+        elif dt[map[opt]] is type(False): state[map[opt]] = True
 
     return args
 
diff --git a/tests/test-issue436 b/tests/test-issue436
--- a/tests/test-issue436
+++ b/tests/test-issue436
@@ -2,5 +2,6 @@
 
 hg init a
 cd a
+hg -v log -v
 hg -v log -v x
 true