diff --git a/Makefile.bootstrapit.make b/Makefile.bootstrapit.make
index 842cfb5..49e4a8d 100644
--- a/Makefile.bootstrapit.make
+++ b/Makefile.bootstrapit.make
@@ -565,6 +565,7 @@ bump_version:
 .PHONY: dist_build
 dist_build:
 	@rm -rf build/lib3to6_out/
+	@rm -rf build/lib/
 	@rm -rf build/bdist*
 	$(DEV_ENV_PY) setup.py sdist;
 	$(DEV_ENV_PY) setup.py bdist_wheel --python-tag=$(BDIST_WHEEL_PYTHON_TAG);