diff -Naur a/setup.py b/setup.py
--- a/setup.py	2010-08-14 15:07:24.000000000 +0200
+++ b/setup.py	2014-05-07 12:53:29.828405018 +0200
@@ -72,7 +72,10 @@
             print "Running tests found in '%s'..." % module
             TEST = __import__(module, globals(), locals(), [])
             suite = loader.loadTestsFromModule(TEST)
-            runner.run(suite)
+            result = runner.run(suite)
+
+	    if len(result.errors) > 0:
+		sys.exit(1);
         
         # restore sys.path
         sys.path = old_path[:]