diff --git a/src/google/adk/code_executors/agent_engine_sandbox_code_executor.py b/src/google/adk/code_executors/agent_engine_sandbox_code_executor.py
index 6634847271..e4bdbc3e03 100644
--- a/src/google/adk/code_executors/agent_engine_sandbox_code_executor.py
+++ b/src/google/adk/code_executors/agent_engine_sandbox_code_executor.py
@@ -174,7 +174,7 @@ def execute_code(
       input_data['files'] = [
           {
               'name': f.name,
-              'contents': f.content,
+              'content': f.content,
               'mimeType': f.mime_type,
           }
           for f in code_execution_input.input_files