diff --git a/src/workflow.py b/src/workflow.py
index e6a05d4..0d7146f 100644
--- a/src/workflow.py
+++ b/src/workflow.py
@@ -5,7 +5,7 @@ import logging
 from src.utils import load_yaml
 from src.machine import MachineManager
 from src.steps import MDStep, SelectStep, SCFStep, TrainStep
-
+import subprocess
 
 class Workflow:
     def __init__(self, root_dir):