diff --git a/neutron_lib/constants.py b/neutron_lib/constants.py
index a49e67a..3af197b 100644
--- a/neutron_lib/constants.py
+++ b/neutron_lib/constants.py
@@ -258,6 +258,10 @@ class Sentinel(object):
         # Always return the same object because this is essentially a constant.
         return self
 
+    def __copy__(self):
+        # called via copy.copy(x)
+        return self
+
 
 #############################
 # Attribute related constants
diff --git a/neutron_lib/tests/unit/test_neutron_lib.py b/neutron_lib/tests/unit/test_neutron_lib.py
index b3aeac9..db5089b 100644
--- a/neutron_lib/tests/unit/test_neutron_lib.py
+++ b/neutron_lib/tests/unit/test_neutron_lib.py
@@ -25,3 +25,7 @@ class TestNeutronLib(base.BaseTestCase):
         foo = constants.Sentinel()
         bar = copy.deepcopy(foo)
         self.assertEqual(id(foo), id(bar))
+
+    def test_sentinel_copy(self):
+        singleton = constants.Sentinel()
+        self.assertEqual(copy.deepcopy(singleton), copy.copy(singleton))