Airports Company South Africa Ltd (ACSA) leased retail premises at King Shaka International Airport to Masiphuze Trading (Pty) Ltd for the operation of a Wimpy franchise. Masiphuze’s shareholders and directors, including Mr Ntavhanyeni Albert Nemukula, signed a deed of suretyship annexed to the lease, binding themselves as sureties and co-principal debtors for Masiphuze’s obligations. Masiphuze later fell into rental arrears, whereupon ACSA cancelled the lease and sued for arrears, damages for holding over, and ejectment, relying on the suretyship. At trial, only Mr Nemukula defended the claim. He alleged that when he signed the lease documents he was unaware that one of them was a deed of suretyship, that manuscript insertions identifying the sureties and principal debtor were added without his authority, and that the suretyship was invalid under s 6 of the General Law Amendment Act 50 of 1956 or unenforceable due to iustus error. The High Court accepted his version and dismissed ACSA’s claim against him.