Field Dependencies Not Working

Field Dependencies Not Working

I've created a field dependency for my CRM account:

If ACCOUNT TYPE = Client, then ACCOUNT STATUS = Active or Inactive
If ACCOUNT TYPE = Prospect, then ACCOUNT STATUS = Null

But when I convert Leads to Contacts and create an Account for the Contact, it automatically sets ACCOUNT TYPE as Prospect and ACCOUNT STATUS as Active. This is against the dependencies I've set up. 

How do I keep this from happening?