diff --git a/selftest/Makefile b/selftest/Makefile
index f0c8c69..fb8618c 100644
--- a/selftest/Makefile
+++ b/selftest/Makefile
@@ -9,4 +9,9 @@
 set_pythonpath:
 	echo "export PYTHONPATH=\"$(PWD)/../src\"" > set_pythonpath
 
+clean:
+	@find . -name "*__pycache__" -type d -print0 | xargs -0 rm -rvf
+	@find . -name "*test_work" -type d -print0 | xargs -0 rm -rvf
+	@rm -fv ./set_pythonpath
+
 # vim: noexpandtab tabstop=8 shiftwidth=8