diff --git a/master/buildbot/test/unit/test_config.py b/master/buildbot/test/unit/test_config.py
index c1f628b5aa8..f678900d2b3 100644
--- a/master/buildbot/test/unit/test_config.py
+++ b/master/buildbot/test/unit/test_config.py
@@ -779,7 +779,7 @@ def test_load_slaves_empty(self):
         name = u""
         self.cfg.load_slaves(self.filename,
                              dict(slaves=[buildslave.BuildSlave(name, 'x')]))
-        self.errors.errors[:] = self.errors.errors[1:2] # only get necessary error
+        self.errors.errors[:] = self.errors.errors[1:2]  # only get necessary error
         self.assertConfigError(self.errors, "cannot be an empty string")
         self.errors.errors[:] = []  # clear out the errors