A breach in psychological contract (PCB) represents inconsistency between employers' promises and actions, which undermines employees' perceptions of their employer corporations' integrity, and can contribute to corporate hypocrisy (CH) among employees. In this light, corporations' sustainability-related promises contradicted by their actual behaviors represent a PCB which can contribute to CH, and this hypocrisy can lead to negative attitudes among employees, decrease in sales, and even business failure. Such corporate behaviors are problems for today's employers to recruit and retain employees as these directly conflict with the millennials' expectations and values. Therefore, today's employers must be ready to communicate and deliver sustainability, to avoid psychological contract breach (PCB) among employees. Thus, the purpose of this paper is to call for corporations' attention as how to reduce PCB regarding corporate sustainability and therefore manage CH among employees. The study recommends a five-step internal marketing management approach for corporations to successfully reduce PCB, as the society demands greater fulfillment of corporate sustainability.