diff --git a/lib/spack/spack/test/__init__.py b/lib/spack/spack/test/__init__.py
index 4b74c7642a..477ea4d581 100644
--- a/lib/spack/spack/test/__init__.py
+++ b/lib/spack/spack/test/__init__.py
@@ -10,4 +10,4 @@ def run(test_name, verbose=False):
 
     verbosity=1
     if verbose: verbosity = 2
-    unittest.main(module=test_module, argv=sys.argv[:1], verbosity=verbosity)
+    unittest.main(module=test_module, argv=sys.argv[:1], verbosity=verbosity, exit=False)