diff --git a/doc/Makefile b/doc/Makefile
index 135bfb4..efe5f22 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -3,7 +3,7 @@
 
 # You can set these variables from the command line.
 SPHINXOPTS    =
-SPHINXBUILD   = sphinx-build
+SPHINXBUILD   = sphinx-build-3
 PAPER         = a4
 BUILDDIR      = _build
 
diff --git a/doc/generate_usage_includes.py b/doc/generate_usage_includes.py
index 257ba51..0182116 100755
--- a/doc/generate_usage_includes.py
+++ b/doc/generate_usage_includes.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import re
 import sys, os