diff --git a/tests/unittests/tools/test_bash_tool.py b/tests/unittests/tools/test_bash_tool.py
index f0f4851990..d2e1e9c0e3 100644
--- a/tests/unittests/tools/test_bash_tool.py
+++ b/tests/unittests/tools/test_bash_tool.py
@@ -252,6 +252,7 @@ async def test_resource_limits_set(self, workspace, tool_context_confirmed):
     )
     tool = bash_tool.ExecuteBashTool(workspace=workspace, policy=policy)
     mock_process = mock.AsyncMock()
+    mock_process.pid = None  # Ensure finally block doesn't try to kill it
     mock_process.communicate.return_value = (b"", b"")
     mock_exec = mock.AsyncMock(return_value=mock_process)