diff --git a/Makefile b/Makefile
index 21cd1682c..87ed34e27 100644
--- a/Makefile
+++ b/Makefile
@@ -33,7 +33,7 @@ coverage:
 	python --version
 	coverage erase
 	DJANGO_SETTINGS_MODULE=tests.settings \
-		coverage run -m django test -v2 $${TEST_ARGS:-tests}
+		python -b -W always -m coverage run -m django test -v2 $${TEST_ARGS:-tests}
 	coverage report
 	coverage html