diff --git a/.apigentools-info b/.apigentools-info
index f51b21876a..ad524756ec 100644
--- a/.apigentools-info
+++ b/.apigentools-info
@@ -4,13 +4,13 @@
     "spec_versions": {
         "v1": {
             "apigentools_version": "1.6.6",
-            "regenerated": "2024-07-19 18:52:07.831612",
-            "spec_repo_commit": "be099b30"
+            "regenerated": "2024-07-19 19:37:56.446276",
+            "spec_repo_commit": "a3f2b7d2"
         },
         "v2": {
             "apigentools_version": "1.6.6",
-            "regenerated": "2024-07-19 18:52:07.850438",
-            "spec_repo_commit": "be099b30"
+            "regenerated": "2024-07-19 19:37:56.463967",
+            "spec_repo_commit": "a3f2b7d2"
         }
     }
 }
\ No newline at end of file
diff --git a/.generator/schemas/v2/openapi.yaml b/.generator/schemas/v2/openapi.yaml
index b8a40a3fbe..1d17a211ad 100644
--- a/.generator/schemas/v2/openapi.yaml
+++ b/.generator/schemas/v2/openapi.yaml
@@ -684,7 +684,7 @@ components:
         created_by:
           $ref: '#/components/schemas/RelationshipToUser'
         modified_by:
-          $ref: '#/components/schemas/RelationshipToUser'
+          $ref: '#/components/schemas/NullableRelationshipToUser'
       type: object
     APIKeyResponse:
       description: Response for retrieving an API key.
diff --git a/src/datadog_api_client/v2/model/api_key_relationships.py b/src/datadog_api_client/v2/model/api_key_relationships.py
index cc14e6fe38..0bfb5caa95 100644
--- a/src/datadog_api_client/v2/model/api_key_relationships.py
+++ b/src/datadog_api_client/v2/model/api_key_relationships.py
@@ -8,6 +8,7 @@
 from datadog_api_client.model_utils import (
     ModelNormal,
     cached_property,
+    none_type,
     unset,
     UnsetType,
 )
@@ -15,16 +16,18 @@
 
 if TYPE_CHECKING:
     from datadog_api_client.v2.model.relationship_to_user import RelationshipToUser
+    from datadog_api_client.v2.model.nullable_relationship_to_user import NullableRelationshipToUser
 
 
 class APIKeyRelationships(ModelNormal):
     @cached_property
     def openapi_types(_):
         from datadog_api_client.v2.model.relationship_to_user import RelationshipToUser
+        from datadog_api_client.v2.model.nullable_relationship_to_user import NullableRelationshipToUser
 
         return {
             "created_by": (RelationshipToUser,),
-            "modified_by": (RelationshipToUser,),
+            "modified_by": (NullableRelationshipToUser,),
         }
 
     attribute_map = {
@@ -35,7 +38,7 @@ def openapi_types(_):
     def __init__(
         self_,
         created_by: Union[RelationshipToUser, UnsetType] = unset,
-        modified_by: Union[RelationshipToUser, UnsetType] = unset,
+        modified_by: Union[NullableRelationshipToUser, none_type, UnsetType] = unset,
         **kwargs,
     ):
         """
@@ -45,7 +48,7 @@ def __init__(
         :type created_by: RelationshipToUser, optional
 
         :param modified_by: Relationship to user.
-        :type modified_by: RelationshipToUser, optional
+        :type modified_by: NullableRelationshipToUser, none_type, optional
         """
         if created_by is not unset:
             kwargs["created_by"] = created_by