Keeping animal companions small?

[technarken]

Is there a way to keep an animal companion, or in my case a Promethean Alchemist Homunculus, from advancing to a higher size category? How does that work?

[Rennaivx]

I know that for standard animal companions,

From the SRD wrote:

Instead of taking the listed benefit at 4th or 7th level (usually the size increase and a couple of stat changes), you can instead choose to increase the companion's Dexterity and Constitution by 2.

I'm not familiar with the alchemist you're talking about, but if it works like an animal companion, you may be able to use that rule. If not, you may see if you could houserule in something along those lines.

[technarken]

Thanks, I think it will work. Now I can keep my little stalker little!