diff --git a/Makefile b/Makefile
index f7f88956..5626a7dc 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,7 @@ PYTHON_BUILD_VERSION ?= 3.8-dev
 PYTHON_BUILD_TEST_PREFIX ?= $(PYTHON_BUILD_ROOT)/test/build/tmp/dist
 
 test-build:
+	$(RM) -r $(PYTHON_BUILD_TEST_PREFIX)
 	$(PYTHON_BUILD_ROOT)/bin/python-build $(PYTHON_BUILD_OPTS) $(PYTHON_BUILD_VERSION) $(PYTHON_BUILD_TEST_PREFIX)
 	[ -e $(PYTHON_BUILD_TEST_PREFIX)/bin/python ]
 	$(PYTHON_BUILD_TEST_PREFIX)/bin/python -V