--- a/tests/runtests.py
+++ b/tests/runtests.py
@@ -41,4 +41,5 @@
     suite.addTest(loader.loadTestsFromName(name))
 
 testRunner = unittest.TextTestRunner()
-testRunner.run(suite)
+result = testRunner.run(suite)
+sys.exit(not result.wasSuccessful())