I want to restrict some accounts to allow transactions only in my base currency (accounts representing bank and cash accounts). But I get the following validation error when raising a customer invoice, implying that the system sees my account as an incorrectly formed foreign currency account rather than just a binding to the base currency.

Error while validating constraint. The selected account of your Journal Entry forces to provide a secondary currency. You should remove the secondary currency on the account.

How can I restrict postings (to base currency)  to a particular account without breaching the constraint?