diff --git a/nova/flags.py b/nova/flags.py
index 7304700f..9eaac559 100644
--- a/nova/flags.py
+++ b/nova/flags.py
@@ -122,6 +122,7 @@ class FlagValues(gflags.FlagValues):
         for k in self.FlagDict().iterkeys():
             new_flags[k] = gflags.FlagValues.__getitem__(self, k)
 
+        new_flags.Reset()
         new_flags(self.__dict__['__stored_argv'])
         for k in new_flags.FlagDict().iterkeys():
             setattr(self, k, getattr(new_flags, k))
diff --git a/nova/tests/test_flags.py b/nova/tests/test_flags.py
index 707300fc..05319d91 100644
--- a/nova/tests/test_flags.py
+++ b/nova/tests/test_flags.py
@@ -91,6 +91,20 @@ class FlagsTestCase(test.TestCase):
         self.assert_('runtime_answer' in self.global_FLAGS)
         self.assertEqual(self.global_FLAGS.runtime_answer, 60)
 
+    def test_long_vs_short_flags(self):
+        flags.DEFINE_string('duplicate_answer_long', 'val', 'desc',
+                            flag_values=self.global_FLAGS)
+        argv = ['flags_test', '--duplicate_answer=60', 'extra_arg']
+        args = self.global_FLAGS(argv)
+
+        self.assert_('duplicate_answer' not in self.global_FLAGS)
+        self.assert_(self.global_FLAGS.duplicate_answer_long, 60)
+
+        flags.DEFINE_integer('duplicate_answer', 60, 'desc',
+                             flag_values=self.global_FLAGS)
+        self.assertEqual(self.global_FLAGS.duplicate_answer, 60)
+        self.assertEqual(self.global_FLAGS.duplicate_answer_long, 'val')
+
     def test_flag_leak_left(self):
         self.assertEqual(FLAGS.flags_unittest, 'foo')
         FLAGS.flags_unittest = 'bar'