diff --git a/ortools/constraint_solver/samples/cvrptw_break.py b/ortools/constraint_solver/samples/cvrptw_break.py
index 8578188bf8..d472387ccc 100755
--- a/ortools/constraint_solver/samples/cvrptw_break.py
+++ b/ortools/constraint_solver/samples/cvrptw_break.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright 2010-2021 Google LLC
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.