diff --git a/Makefile b/Makefile
index c36fbd8..f2d05d9 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ TAGS: ${SOURCES}
 tags: ${SOURCES}
 	ctags -R testtools/
 
-clean:
+clean: clean-sphinx
 	rm -f TAGS tags
 	find testtools -name "*.pyc" -exec rm '{}' \;
 
@@ -26,10 +26,24 @@ release:
 snapshot: prerelease
 	./setup.py sdist
 
+### Documentation ###
+
 apidocs:
 	pydoctor --make-html --add-package testtools \
 		--docformat=restructuredtext --project-name=testtools \
 		--project-url=https://launchpad.net/testtools
 
+docs: docs-sphinx
 
-.PHONY: check clean prerelease release apidocs
+docs-sphinx: html-sphinx
+
+# Clean out generated documentation
+clean-sphinx:
+	cd doc && make clean
+
+# Build the html docs using Sphinx.
+html-sphinx:
+	cd doc && make html
+
+.PHONY: apidocs docs-sphinx clean-sphinx html-sphinx docs
+.PHONY: check clean prerelease release