Modded fluid bucket using vanilla bucket?

Hello internet, I'm in the process of creating a mod (of course), and I ran into a problem with fluids and buckets. The fluid bucket itself needed to be added manually instead of being a premade MCreator bucket, as I would like to include it in a crafting recipe. But an issue arose with trying to use the vanilla iron bucket in conjunction with a modded fluid bucket... If you have anything to say on this topic, please do; I'm losing my sanity.