Use an options struct for Resize.
diff --git a/openstack/compute/v2/servers/requests_test.go b/openstack/compute/v2/servers/requests_test.go
index 5b65d86..f3b8a7f 100644
--- a/openstack/compute/v2/servers/requests_test.go
+++ b/openstack/compute/v2/servers/requests_test.go
@@ -172,7 +172,7 @@
 		w.WriteHeader(http.StatusAccepted)
 	})
 
-	res := Resize(client.ServiceClient(), "1234asdf", "2")
+	res := Resize(client.ServiceClient(), "1234asdf", ResizeOpts{FlavorRef: "2"})
 	th.AssertNoErr(t, res.Err)
 }