diff --git a/neutron/quota.py b/neutron/quota.py
index ae718cb..3cf8e11 100644
--- a/neutron/quota.py
+++ b/neutron/quota.py
@@ -156,9 +156,12 @@ class BaseResource(object):
     @property
     def default(self):
         """Return the default value of the quota."""
-        return getattr(cfg.CONF.QUOTAS,
-                       self.flag,
-                       cfg.CONF.QUOTAS.default_quota)
+        # Any negative value will be interpreted as an infinite quota,
+        # and stored as -1 for compatibility with current behaviour
+        value = getattr(cfg.CONF.QUOTAS,
+                        self.flag,
+                        cfg.CONF.QUOTAS.default_quota)
+        return max(value, -1)
 
 
 class CountableResource(BaseResource):
diff --git a/neutron/tests/unit/test_quota_ext.py b/neutron/tests/unit/test_quota_ext.py
index 608d9fb..3195ecf 100644
--- a/neutron/tests/unit/test_quota_ext.py
+++ b/neutron/tests/unit/test_quota_ext.py
@@ -79,6 +79,16 @@ class QuotaExtensionTestCase(testlib_api.WebTestCase):
         attributes.RESOURCE_ATTRIBUTE_MAP = self.saved_attr_map
         super(QuotaExtensionTestCase, self).tearDown()
 
+    def _test_quota_default_values(self, expected_values):
+        tenant_id = 'tenant_id1'
+        env = {'neutron.context': context.Context('', tenant_id)}
+        res = self.api.get(_get_path('quotas', id=tenant_id, fmt=self.fmt),
+                           extra_environ=env)
+        quota = self.deserialize(res)
+        for resource in expected_values:
+            self.assertEqual(expected_values[resource],
+                             quota['quota'][resource])
+
 
 class QuotaExtensionDbTestCase(QuotaExtensionTestCase):
     fmt = 'json'
@@ -97,15 +107,20 @@ class QuotaExtensionDbTestCase(QuotaExtensionTestCase):
         self.assertEqual(200, res.status_int)
 
     def test_quotas_default_values(self):
-        tenant_id = 'tenant_id1'
-        env = {'neutron.context': context.Context('', tenant_id)}
-        res = self.api.get(_get_path('quotas', id=tenant_id, fmt=self.fmt),
-                           extra_environ=env)
-        quota = self.deserialize(res)
-        self.assertEqual(10, quota['quota']['network'])
-        self.assertEqual(10, quota['quota']['subnet'])
-        self.assertEqual(50, quota['quota']['port'])
-        self.assertEqual(-1, quota['quota']['extra1'])
+        self._test_quota_default_values(
+            {'network': 10,
+             'subnet': 10,
+             'port': 50,
+             'extra1': -1})
+
+    def test_quotas_negative_default_value(self):
+        cfg.CONF.set_override(
+            'quota_port', -666, group='QUOTAS')
+        self._test_quota_default_values(
+            {'network': 10,
+             'subnet': 10,
+             'port': -1,
+             'extra1': -1})
 
     def test_show_quotas_with_admin(self):
         tenant_id = 'tenant_id1'
@@ -337,15 +352,20 @@ class QuotaExtensionCfgTestCase(QuotaExtensionTestCase):
         super(QuotaExtensionCfgTestCase, self).setUp()
 
     def test_quotas_default_values(self):
-        tenant_id = 'tenant_id1'
-        env = {'neutron.context': context.Context('', tenant_id)}
-        res = self.api.get(_get_path('quotas', id=tenant_id, fmt=self.fmt),
-                           extra_environ=env)
-        quota = self.deserialize(res)
-        self.assertEqual(10, quota['quota']['network'])
-        self.assertEqual(10, quota['quota']['subnet'])
-        self.assertEqual(50, quota['quota']['port'])
-        self.assertEqual(-1, quota['quota']['extra1'])
+        self._test_quota_default_values(
+            {'network': 10,
+             'subnet': 10,
+             'port': 50,
+             'extra1': -1})
+
+    def test_quotas_negative_default_value(self):
+        cfg.CONF.set_override(
+            'quota_port', -666, group='QUOTAS')
+        self._test_quota_default_values(
+            {'network': 10,
+             'subnet': 10,
+             'port': -1,
+             'extra1': -1})
 
     def test_show_quotas_with_admin(self):
         tenant_id = 'tenant_id1'