diff --git a/examples/MDF/simple.py b/examples/MDF/simple.py
index 43816363..df08945b 100644
--- a/examples/MDF/simple.py
+++ b/examples/MDF/simple.py
@@ -2,6 +2,7 @@
     Example of ModECI MDF - A simple 2 node graph.
 """
 
+import os
 from modeci_mdf.mdf import (
     Model,
     Graph,