diff --git a/src/google/adk/evaluation/local_eval_set_results_manager.py b/src/google/adk/evaluation/local_eval_set_results_manager.py
index d1e597c9a1..f25dfc9642 100644
--- a/src/google/adk/evaluation/local_eval_set_results_manager.py
+++ b/src/google/adk/evaluation/local_eval_set_results_manager.py
@@ -54,7 +54,7 @@ def save_eval_set_result(
     if not os.path.exists(app_eval_history_dir):
       os.makedirs(app_eval_history_dir)
     # Convert to json and write to file.
-    eval_set_result_json = eval_set_result.model_dump_json()
+    eval_set_result_json = eval_set_result.model_dump(mode="json")
     eval_set_result_file_path = os.path.join(
         app_eval_history_dir,
         eval_set_result.eval_set_result_name + _EVAL_SET_RESULT_FILE_EXTENSION,
@@ -80,7 +80,7 @@ def get_eval_set_result(
       raise NotFoundError(f"Eval set result `{eval_set_result_id}` not found.")
     with open(maybe_eval_result_file_path, "r", encoding="utf-8") as file:
       eval_result_data = json.load(file)
-    return EvalSetResult.model_validate_json(eval_result_data)
+    return EvalSetResult.model_validate(eval_result_data)
 
   @override
   def list_eval_set_results(self, app_name: str) -> list[str]:
diff --git a/tests/unittests/evaluation/test_local_eval_set_results_manager.py b/tests/unittests/evaluation/test_local_eval_set_results_manager.py
index 45500d71c5..b3a4be32f6 100644
--- a/tests/unittests/evaluation/test_local_eval_set_results_manager.py
+++ b/tests/unittests/evaluation/test_local_eval_set_results_manager.py
@@ -88,7 +88,7 @@ def test_save_eval_set_result(self, mocker):
       actual_eval_set_result_json = json.load(f)
 
     # need to convert eval_set_result to json
-    expected_eval_set_result_json = self.eval_set_result.model_dump_json()
+    expected_eval_set_result_json = self.eval_set_result.model_dump(mode="json")
     assert expected_eval_set_result_json == actual_eval_set_result_json
 
   def test_get_eval_set_result(self, mocker):