Beliefs and values are hard to alter; yet they strongly influence employees' attitudes towards strategic changes. Using a longitudinal case study in the oil industry, we show how to distinguish between ideological beliefs (justified by ethical values) and mundane beliefs (substantiated by knowledge structures). We explain that the willingness of workers to participate in change was promoted by a dynamic interaction between these interdependent belief sets. More critically, we show that acceptance of change did not require a change in values, but rather a change in the way that values were applied. We develop propositions that move theory forward and point to future directions for research.