diff --git a/ironic/api/controllers/v1/port.py b/ironic/api/controllers/v1/port.py
index 1943075ae0..53be406e8b 100644
--- a/ironic/api/controllers/v1/port.py
+++ b/ironic/api/controllers/v1/port.py
@@ -60,13 +60,13 @@ PORT_SCHEMA = {
 
 
 PORT_PATCH_SCHEMA = copy.deepcopy(PORT_SCHEMA)
-# patch supports patching some internal_info values
+# patching /extra/vif_port_id has the side-effect of modifying
+# internal_info values, so include it in the patch schema
 PORT_PATCH_SCHEMA['properties']['internal_info'] = {'type': ['null', 'object']}
 
 PATCH_ALLOWED_FIELDS = [
     'address',
     'extra',
-    'internal_info',
     'is_smartnic',
     'local_link_connection',
     'node_uuid',
diff --git a/ironic/api/controllers/v1/portgroup.py b/ironic/api/controllers/v1/portgroup.py
index e1e49d6520..6e57ff78fb 100644
--- a/ironic/api/controllers/v1/portgroup.py
+++ b/ironic/api/controllers/v1/portgroup.py
@@ -52,7 +52,8 @@ PORTGROUP_SCHEMA = {
 }
 
 PORTGROUP_PATCH_SCHEMA = copy.deepcopy(PORTGROUP_SCHEMA)
-# patch supports patching some internal_info values
+# patching /extra/vif_port_id has the side-effect of modifying
+# internal_info values, so include it in the patch schema
 PORTGROUP_PATCH_SCHEMA['properties']['internal_info'] = {
     'type': ['null', 'object']}