diff --git a/neutron/db/l3_db.py b/neutron/db/l3_db.py
index bd7421b98ea..d5d479a326e 100644
--- a/neutron/db/l3_db.py
+++ b/neutron/db/l3_db.py
@@ -1024,7 +1024,7 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase,
                     data = {'floatingip_id': fip['id'],
                             'internal_ip': internal_ip_address}
                     msg = (_('Floating IP %(floatingip_id)s is associated '
-                             'with non-IPv4 address %s(internal_ip)s and '
+                             'with non-IPv4 address %(internal_ip)s and '
                              'therefore cannot be bound.') % data)
                 else:
                     msg = (_('Cannot create floating IP and bind it to %s, '
diff --git a/neutron/tests/unit/extensions/test_l3.py b/neutron/tests/unit/extensions/test_l3.py
index 52335d2eef8..e7f8382cf5e 100644
--- a/neutron/tests/unit/extensions/test_l3.py
+++ b/neutron/tests/unit/extensions/test_l3.py
@@ -2096,6 +2096,17 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
                     self.assertEqual(str(ip_range[-2]),
                                      body_2['floatingip']['fixed_ip_address'])
 
+    def test_floatingip_update_invalid_fixed_ip(self):
+        with self.subnet() as s:
+            with self.port(subnet=s) as p:
+                with self.floatingip_with_assoc(
+                    port_id=p['port']['id']) as fip:
+                    self._update(
+                        'floatingips', fip['floatingip']['id'],
+                        {'floatingip': {'port_id': p['port']['id'],
+                                        'fixed_ip_address': '2001:db8::a'}},
+                        expected_code=exc.HTTPBadRequest.code)
+
     def test_first_floatingip_associate_notification(self):
         with self.port() as p:
             private_sub = {'subnet': {'id':
@@ -2402,6 +2413,12 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
                                       uuidutils.generate_uuid(), 'iamnotnanip')
         self.assertEqual(400, res.status_int)
 
+    def test_create_floatingip_invalid_fixed_ipv6_address_returns_400(self):
+        # API-level test - no need to create all objects for l3 plugin
+        res = self._create_floatingip(self.fmt, uuidutils.generate_uuid(),
+                                      uuidutils.generate_uuid(), '2001:db8::a')
+        self.assertEqual(400, res.status_int)
+
     def test_floatingip_list_with_sort(self):
         with self.subnet(cidr="10.0.0.0/24") as s1,\
                 self.subnet(cidr="11.0.0.0/24") as s2,\