diff --git a/regtests/0252_spws/test.py b/regtests/0252_spws/test.py
index 0e1b989..3b098d4 100644
--- a/regtests/0252_spws/test.py
+++ b/regtests/0252_spws/test.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 #                              Ada Web Server
 #
 #                     Copyright (C) 2014-2015, AdaCore
diff --git a/regtests/gen_system_tags.py b/regtests/gen_system_tags.py
index 71e4f12..2d613db 100755
--- a/regtests/gen_system_tags.py
+++ b/regtests/gen_system_tags.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 """
 ./gen_system_tags.py /path/to/aws/makefile.setup
 
diff --git a/regtests/run-test b/regtests/run-test
index a9b207c..25baa7f 100644
--- a/regtests/run-test
+++ b/regtests/run-test
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 """Usage: run-test [options] test_dir
 
 Run a single test located in test_dir
diff --git a/regtests/testsuite.py b/regtests/testsuite.py
index 8308361..d7c9fd1 100755
--- a/regtests/testsuite.py
+++ b/regtests/testsuite.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 #                              Ada Web Server
 #
 #                     Copyright (C) 2003-2020, AdaCore