diff --git a/doc/Makefile b/doc/Makefile
index a0b1e46b7fa11f3ec117e2c99d89c44c573b067b..33f9546f2dabad7d1deefa6cbaf4416b8aba0d18 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -30,11 +30,11 @@ clean:
 	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
 
 latex: Makefile $(GENERATEDPDF)
-	cd .. ; python setup.py build ; cd -
+	cd .. ; python3 setup.py build ; cd -
 	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
 
 # Catch-all target: route all unknown targets to Sphinx using the new
 # "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
 %: Makefile
-	cd .. ; python setup.py build ; cd -
+	cd .. ; python3 setup.py build ; cd -
 	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)