diff --git a/mbtrack2/tracking/parallel.py b/mbtrack2/tracking/parallel.py
index 6ef184614be7fb356d32bb783750986d0889825f..aa3872d1e57a5b616236a8428a3fef622c9e41ad 100644
--- a/mbtrack2/tracking/parallel.py
+++ b/mbtrack2/tracking/parallel.py
@@ -4,6 +4,7 @@ Module to handle parallel computation
 """
 
 import numpy as np
+import sys
 
 
 class Mpi: