A supplementary agreement may operate to displace the operation of the termination provisions of the original contract. In Orion-One Residential Pte Ltd v Dong Cheng Construction Pte Ltd and another [2020] SGCA 121, the original contract was based on the REDAS Form. The parties subsequently entered into a supplementary agreement. When disputes arose, the employer terminated the contractor’s employment pursuant to a clause in the supplementary agreement. As a result, the Court of Appeal held that the contractor was not entitled to rely on the REDAS provisions regulating the service of payment claims following the termination of the employer.