21. Any provision in a contract of service or other agreement between an employer and an employee is void in so far as it –
(a) purports to exclude any provision of this Act, including an agreement to refrain from instituting or continuing any proceedings under this Act or any proceedings for breach of contract; or
(b) purports to preclude the employee or has the effect of discouraging the employee from making a protected disclosure in terms of this Act.
Referenced Legislation: Protection of the Whistleblower Act (2013)