diff --git a/Makefile b/Makefile
index 08d0322..323fe4c 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ lint: test_deps
 	./setup.py flake8
 
 test: test_deps lint
-	coverage run --source=$$(python setup.py --name) ./test/test.py
+	coverage run --source=$$(python setup.py --name | sed 's/-/_/g') ./test/test.py
 
 init_docs:
 	cd docs; sphinx-quickstart