$ git diff f0b4d55bd98e5d1a9089399dc7ecee2c75ecc6a8 provider/maas/bridgescript_test.go
diff --git a/provider/maas/bridgescript_test.go b/provider/maas/bridgescript_test.go
index 90986d3..a50f2bd 100644
--- a/provider/maas/bridgescript_test.go
+++ b/provider/maas/bridgescript_test.go
@@ -70,7 +70,7 @@ func (s *bridgeConfigSuite) assertScript(c *gc.C, initialConfig, expectedConfig,
                // Run the script and verify the modified config.
                output, retcode := s.runScript(c, python, s.testConfigPath, bridgePrefix, bridgeName, interfaceToBridge)
                c.Check(retcode, gc.Equals, 0)
-               c.Check(strings.Trim(output, "\n"), gc.Equals, expectedConfig)
+               c.Check(strings.Trim(output, "\n"), gc.Equals, expectedConfig, gc.Commentf("initial was:\n%s", initialConfig))
        }
 }