diff --git a/aws_lambda_powertools/utilities/parser/models/apigwv2.py b/aws_lambda_powertools/utilities/parser/models/apigwv2.py
index 943d42a8e01..540e7c1a30b 100644
--- a/aws_lambda_powertools/utilities/parser/models/apigwv2.py
+++ b/aws_lambda_powertools/utilities/parser/models/apigwv2.py
@@ -72,4 +72,4 @@ class APIGatewayProxyEventV2Model(BaseModel):
 class ApiGatewayAuthorizerRequestV2(APIGatewayProxyEventV2Model):
     type: Literal["REQUEST"]
     routeArn: str
-    identitySource: List[str]
+    identitySource: Optional[List[str]] = None
diff --git a/tests/unit/parser/_pydantic/test_apigwv2.py b/tests/unit/parser/_pydantic/test_apigwv2.py
index cec9e05bccd..ddb849bb68a 100644
--- a/tests/unit/parser/_pydantic/test_apigwv2.py
+++ b/tests/unit/parser/_pydantic/test_apigwv2.py
@@ -130,3 +130,12 @@ def test_apigw_v2_request_authorizer():
     assert parsed_event.type == raw_event["type"]
     assert parsed_event.identitySource == raw_event["identitySource"]
     assert parsed_event.routeArn == raw_event["routeArn"]
+
+
+def test_apigw_v2_request_authorizer_without_identity_source():
+    raw_event = load_event("apiGatewayAuthorizerV2Event.json")
+    raw_event["identitySource"] = None
+
+    parsed_event: ApiGatewayAuthorizerRequestV2 = ApiGatewayAuthorizerRequestV2(**raw_event)
+
+    assert parsed_event.identitySource == raw_event["identitySource"]