diff --git a/neutron_lib/api/definitions/subnet.py b/neutron_lib/api/definitions/subnet.py
index 33644c723..0bb3b1248 100644
--- a/neutron_lib/api/definitions/subnet.py
+++ b/neutron_lib/api/definitions/subnet.py
@@ -68,6 +68,7 @@ RESOURCE_ATTRIBUTE_MAP = {
         'cidr': {'allow_post': True,
                  'allow_put': False,
                  'default': constants.ATTR_NOT_SPECIFIED,
+                 'convert_to': converters.convert_cidr_to_canonical_format,
                  'validate': {'type:subnet_or_none': None},
                  'required_by_policy': False,
                  'is_filter': True,
@@ -75,14 +76,17 @@ RESOURCE_ATTRIBUTE_MAP = {
                  'is_visible': True},
         'gateway_ip': {'allow_post': True, 'allow_put': True,
                        'default': constants.ATTR_NOT_SPECIFIED,
+                       'convert_to': converters.convert_ip_to_canonical_format,
                        'validate': {'type:ip_address_or_none': None},
                        'is_filter': True,
                        'is_sort_key': True,
                        'is_visible': True},
-        'allocation_pools': {'allow_post': True, 'allow_put': True,
-                             'default': constants.ATTR_NOT_SPECIFIED,
-                             'validate': {'type:ip_pools': None},
-                             'is_visible': True},
+        'allocation_pools': {
+            'allow_post': True, 'allow_put': True,
+            'default': constants.ATTR_NOT_SPECIFIED,
+            'convert_to': converters.convert_ip_to_canonical_format,
+            'validate': {'type:ip_pools': None},
+            'is_visible': True},
         'dns_nameservers': {'allow_post': True, 'allow_put': True,
                             'convert_to':
                                 converters.convert_none_to_empty_list,
diff --git a/releasenotes/notes/ipv6-canonical-address-13900a784f847ce3.yaml b/releasenotes/notes/ipv6-canonical-address-13900a784f847ce3.yaml
new file mode 100644
index 000000000..f3af7e761
--- /dev/null
+++ b/releasenotes/notes/ipv6-canonical-address-13900a784f847ce3.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    The ``gateway`` , ``allocation_pools`` and ``cidr`` attributes of a Subnet with IPv6 addresses
+    are now converted to IPv6 canonical format to address.
+    `bug 1531103 <https://bugs.launchpad.net/neutron/+bug/1531103>`_