diff --git a/accelerator/mps_accelerator.py b/accelerator/mps_accelerator.py
index ee3ba4ca574f..ff70b860d7c7 100644
--- a/accelerator/mps_accelerator.py
+++ b/accelerator/mps_accelerator.py
@@ -259,6 +259,7 @@ def build_extension(self):
     def export_envs(self):
         return []
 
+    # TODO: mpu's visible envs is confirmed, keep as CUDA_VISIBLE_DEVICES
     def visible_devices_envs(self):
         # TODO: could not find visible devices env for mps
         return ['CUDA_VISIBLE_DEVICES']