diff --git a/lib/spack/spack/test/mock_database.py b/lib/spack/spack/test/mock_database.py
index 6fd05439bff2ec8d2e8f06dd2d284c2a57f14b3b..82ba59fc4834c6a5194b88bbcf59729d9e0ee103 100644
--- a/lib/spack/spack/test/mock_database.py
+++ b/lib/spack/spack/test/mock_database.py
@@ -17,7 +17,7 @@ def _mock_install(self, spec):
 
     def _mock_remove(self, spec):
         specs = spack.installed_db.query(spec)
-        assert(len(specs) == 1)
+        assert len(specs) == 1
         spec = specs[0]
         spec.package.do_uninstall(spec)
 
@@ -71,6 +71,8 @@ def setUp(self):
             self._mock_install('mpileaks ^zmpi')
 
     def tearDown(self):
+        for spec in spack.installed_db.query():
+            spec.package.do_uninstall(spec)
         super(MockDatabase, self).tearDown()
         shutil.rmtree(self.install_path)
         spack.install_path = self.spack_install_path