diff --git a/man/Makefile b/man/Makefile
index 841432f..61de877 100644
--- a/man/Makefile
+++ b/man/Makefile
@@ -3,7 +3,7 @@ RST2MAN=rst2man -d -t
 default: man1/irpman.1.gz man1/irpf90.1.gz
 
 options.rst: ../src/command_line.py
-	python ../src/command_line.py > options.rst
+	python3 ../src/command_line.py > options.rst
 
 man1/irpf90.1.gz: irpf90.rst options.rst
 	rm -f $@ ; $(RST2MAN) --title="IRP Fortran 90" irpf90.rst man1/irpf90.1 ; gzip man1/irpf90.1
diff --git a/pip/irpf90 b/pip/irpf90
index bccc151..040fb46 100755
--- a/pip/irpf90
+++ b/pip/irpf90
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #   IRPF90 is a Fortran90 preprocessor written in Python for programming using
 #   the Implicit Reference to Parameters (IRP) method.
 #   Copyright (C) 2009 Anthony SCEMAMA 
diff --git a/pip/irpf90_indent b/pip/irpf90_indent
index c9353e7..d7d59e9 100755
--- a/pip/irpf90_indent
+++ b/pip/irpf90_indent
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #   IRPF90 is a Fortran90 preprocessor written in Python for programming using
 #   the Implicit Reference to Parameters (IRP) method.
 #   Copyright (C) 2009 Anthony SCEMAMA 
diff --git a/src/preprocessed_text.py b/src/preprocessed_text.py
index a4cae1b..3379c8b 100644
--- a/src/preprocessed_text.py
+++ b/src/preprocessed_text.py
@@ -323,7 +323,7 @@ def execute_templates(text):
         file.close()
         # Execute shell
         import os
-        pipe = os.popen("python < %s"%(scriptname),'r')
+        pipe = os.popen("python3 < %s"%(scriptname),'r')
         lines = pipe.readlines()
         pipe.close()
         result += get_text(lines,scriptname)