diff --git a/ironic/api/controllers/v1/chassis.py b/ironic/api/controllers/v1/chassis.py
index 1394a1b7ce..73f32c22d1 100644
--- a/ironic/api/controllers/v1/chassis.py
+++ b/ironic/api/controllers/v1/chassis.py
@@ -151,24 +151,29 @@ class ChassisController(rest.RestController):
         chassis = objects.Chassis.get_by_uuid(pecan.request.context, uuid)
         chassis_dict = chassis.as_dict()
 
-        # These are internal values that shouldn't be part of the patch
-        internal_attrs = ['id', 'updated_at', 'created_at']
-        [chassis_dict.pop(attr, None) for attr in internal_attrs]
-
         utils.validate_patch(patch)
         try:
-            final_patch = jsonpatch.apply_patch(chassis_dict,
-                                                jsonpatch.JsonPatch(patch))
+            patched_chassis = jsonpatch.apply_patch(chassis_dict,
+                                                    jsonpatch.JsonPatch(patch))
         except jsonpatch.JsonPatchException as e:
             LOG.exception(e)
             raise wsme.exc.ClientSideError(_("Patching Error: %s") % e)
 
-        # In case of a remove operation, add the missing fields back to
-        # the document with their default value
         defaults = objects.Chassis.get_defaults()
-        defaults.update(final_patch)
+        for key in defaults:
+            # Internal values that shouldn't be part of the patch
+            if key in ['id', 'updated_at', 'created_at']:
+                continue
+
+            # In case of a remove operation, add the missing fields back
+            # to the document with their default value
+            if key in chassis_dict and key not in patched_chassis:
+                patched_chassis[key] = defaults[key]
+
+            # Update only the fields that have changed
+            if chassis[key] != patched_chassis[key]:
+                chassis[key] = patched_chassis[key]
 
-        chassis.update(defaults)
         chassis.save()
         return Chassis.convert_with_links(chassis)
 
diff --git a/ironic/api/controllers/v1/node.py b/ironic/api/controllers/v1/node.py
index bfa41124ee..b87108a118 100644
--- a/ironic/api/controllers/v1/node.py
+++ b/ironic/api/controllers/v1/node.py
@@ -337,10 +337,6 @@ class NodesController(rest.RestController):
         node = objects.Node.get_by_uuid(pecan.request.context, uuid)
         node_dict = node.as_dict()
 
-        # These are internal values that shouldn't be part of the patch
-        internal_attrs = ['id', 'updated_at', 'created_at']
-        [node_dict.pop(attr, None) for attr in internal_attrs]
-
         utils.validate_patch(patch)
         patch_obj = jsonpatch.JsonPatch(patch)
 
@@ -362,19 +358,28 @@ class NodesController(rest.RestController):
                                              "progress.") % uuid)
 
         try:
-            final_patch = jsonpatch.apply_patch(node_dict, patch_obj)
+            patched_node = jsonpatch.apply_patch(node_dict, patch_obj)
         except jsonpatch.JsonPatchException as e:
             LOG.exception(e)
             raise wsme.exc.ClientSideError(_("Patching Error: %s") % e)
 
         response = wsme.api.Response(Node(), status_code=200)
         try:
-            # In case of a remove operation, add the missing fields back to
-            # the document with their default value
             defaults = objects.Node.get_defaults()
-            defaults.update(final_patch)
+            for key in defaults:
+                # Internal values that shouldn't be part of the patch
+                if key in ['id', 'updated_at', 'created_at']:
+                    continue
+
+                # In case of a remove operation, add the missing fields back
+                # to the document with their default value
+                if key in node_dict and key not in patched_node:
+                    patched_node[key] = defaults[key]
+
+                # Update only the fields that have changed
+                if node[key] != patched_node[key]:
+                    node[key] = patched_node[key]
 
-            node.update(defaults)
             node = pecan.request.rpcapi.update_node(pecan.request.context,
                                                     node)
             response.obj = node
diff --git a/ironic/api/controllers/v1/port.py b/ironic/api/controllers/v1/port.py
index 6300de9064..d4b6052b09 100644
--- a/ironic/api/controllers/v1/port.py
+++ b/ironic/api/controllers/v1/port.py
@@ -130,24 +130,29 @@ class PortsController(rest.RestController):
         port = objects.Port.get_by_uuid(pecan.request.context, uuid)
         port_dict = port.as_dict()
 
-        # These are internal values that shouldn't be part of the patch
-        internal_attrs = ['id', 'updated_at', 'created_at']
-        [port_dict.pop(attr, None) for attr in internal_attrs]
-
         utils.validate_patch(patch)
         try:
-            final_patch = jsonpatch.apply_patch(port_dict,
-                                                jsonpatch.JsonPatch(patch))
+            patched_port = jsonpatch.apply_patch(port_dict,
+                                                 jsonpatch.JsonPatch(patch))
         except jsonpatch.JsonPatchException as e:
             LOG.exception(e)
             raise wsme.exc.ClientSideError(_("Patching Error: %s") % e)
 
-        # In case of a remove operation, add the missing fields back to
-        # the document with their default value
         defaults = objects.Port.get_defaults()
-        defaults.update(final_patch)
+        for key in defaults:
+            # Internal values that shouldn't be part of the patch
+            if key in ['id', 'updated_at', 'created_at']:
+                continue
+
+            # In case of a remove operation, add the missing fields back
+            # to the document with their default value
+            if key in port_dict and key not in patched_port:
+                patched_port[key] = defaults[key]
+
+            # Update only the fields that have changed
+            if port[key] != patched_port[key]:
+                port[key] = patched_port[key]
 
-        port.update(defaults)
         port.save()
         return Port.convert_with_links(port)