Case insensitive Auto-Tag?

I have a topic TV of input type Auto-Tag. Problem is, the users of the site are adding topics sometimes capitalized, sometimes not, sometimes mixed—e.g. "Production Cost", "production cost", "Production cost". This creates three different tags when it should only be one.

Is there some way to make Auto-Tag case insensitive, preventing this problem?

Not sure if there is a way to handle this other than either modifying the auto-tag TV to force to lowercase or to instruct users to be consistent with the input formatting via description text.