additionally return 'error' from 'ToCreateServerMap'
diff --git a/rackspace/compute/v2/servers/requests_test.go b/rackspace/compute/v2/servers/requests_test.go
index ac7058f..3c0f806 100644
--- a/rackspace/compute/v2/servers/requests_test.go
+++ b/rackspace/compute/v2/servers/requests_test.go
@@ -27,7 +27,9 @@
 		}
 	}
 	`
-	th.CheckJSONEquals(t, expected, opts.ToServerCreateMap())
+	actual, err := opts.ToServerCreateMap()
+	th.AssertNoErr(t, err)
+	th.CheckJSONEquals(t, expected, actual)
 }
 
 func TestRebuildOpts(t *testing.T) {