diff --git a/heat/common/exception.py b/heat/common/exception.py
index 3205e36cc5..8ef78e2d5f 100644
--- a/heat/common/exception.py
+++ b/heat/common/exception.py
@@ -355,7 +355,7 @@ class ResourcePropertyValueDependency(HeatException):
 
 class PropertyUnspecifiedError(HeatException):
     msg_fmt = _('At least one of the following properties '
-                'must be specified: %(props)s')
+                'must be specified: %(props)s.')
 
     def __init__(self, *args, **kwargs):
         if args:
diff --git a/heat/tests/openstack/neutron/test_neutron_router.py b/heat/tests/openstack/neutron/test_neutron_router.py
index e929ff17ec..1638e7b616 100644
--- a/heat/tests/openstack/neutron/test_neutron_router.py
+++ b/heat/tests/openstack/neutron/test_neutron_router.py
@@ -689,7 +689,7 @@ class NeutronRouterTest(common.HeatTestCase):
         ex = self.assertRaises(exception.PropertyUnspecifiedError,
                                res.validate)
         self.assertEqual("At least one of the following properties "
-                         "must be specified: subnet, port",
+                         "must be specified: subnet, port.",
                          six.text_type(ex))
         self.m.VerifyAll()
 
diff --git a/heat/tests/openstack/neutron/test_neutron_subnet.py b/heat/tests/openstack/neutron/test_neutron_subnet.py
index ccce450f0f..3a70dd6b87 100644
--- a/heat/tests/openstack/neutron/test_neutron_subnet.py
+++ b/heat/tests/openstack/neutron/test_neutron_subnet.py
@@ -677,7 +677,7 @@ class NeutronSubnetTest(common.HeatTestCase):
         ex = self.assertRaises(exception.PropertyUnspecifiedError,
                                rsrc.validate)
         msg = ("At least one of the following properties must be specified: "
-               "subnetpool, cidr")
+               "subnetpool, cidr.")
         self.assertEqual(msg, six.text_type(ex))
 
     def test_validate_both_prefixlen_cidr(self):