Promising to perform a pre-existing duty owed to one's contracting party also fails to make good consideration. However this rule has been considerably narrowed by recent case law. The general rule is that if a creditor promises to discharge a debt in return for a fraction of payment, in paying the agreed fraction, the promisee is not providing consideration for the promise, as this is merely part performance of a contractual duty already owed. Consequently, the debtor is still liable for the whole amount, as he cannot force the promisor to accept less. A leading example is in "Stilk v Myrick" where Stilk, a seaman, agreed with Myrick to sail his boat to the Baltic Sea and back for £5 per month. During the voyage, two men deserted. Myrick promised he would increase Stilk's wages if Stilk agreed to honour his contract in light of the desertions. Stilk agreed and on return to port, Myrick refused to pay him the extra wages. It was held that Myrick's fresh promise was not enforceable as the consideration Stilk had provided for it, the performance of a duty he already owed to Myrick under contract, was not good consideration for Myrick's promise to increase his wages.