diff --git a/Makefile b/Makefile
index 58b3ceb..3631b49 100644
--- a/Makefile
+++ b/Makefile
@@ -17,6 +17,10 @@ clean: ## clean the repository
 	find . -name "__pycache__" | xargs  rm -rf 
 	find . -name "*.pyc" | xargs rm -rf 
 	rm -rf .coverage cover htmlcov logs build dist *.egg-info
+	make -C ./docs clean
+
+docs:  ## make documentation
+	make -C ./docs html
 
 install:  ## install to site-packages
 	python3 setup.py install
@@ -29,4 +33,4 @@ help:
 print-%:
 	@echo '$*=$($*)'
 
-.PHONY: clean test tests help annotate annotate_l
+.PHONY: clean test tests help annotate annotate_l docs