diff --git a/ci-gui.py b/ci-gui.py
index 20f4526..8b82fc3 100644
--- a/ci-gui.py
+++ b/ci-gui.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 # This file is a part of custom-install.py.
 #
 # custom-install is copyright (c) 2019-2020 Ian Burgwin
diff --git a/custominstall.py b/custominstall.py
index 04a039c..5580c18 100644
--- a/custominstall.py
+++ b/custominstall.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 # This file is a part of custom-install.py.
 #
 # custom-install is copyright (c) 2019-2020 Ian Burgwin