diff --git a/val_sim.py b/val_sim.py
index 347059771cb35bea69f16c5fec9e6593a66a7b9a..d0f74c6aad9e846d4a5185b3f20d62cefdb92efc 100644
--- a/val_sim.py
+++ b/val_sim.py
@@ -1,3 +1,4 @@
+#!/usr/bin/python3
 import json
 import sys