Software evolution is a major challenge to software development. When adapting a system model to new, altered or deleted requirements, existing requirements should not unintentionally be violated. One requirement can affect several possibly unassociated elements of a system. A new constraint technique is introduced in this paper: One context-based constraint (CoCon) specifies a requirement for those system (model) elements that belong to the related context. The constrained elements are indirectly selected via their meta-information. Thus, verifying compliance with requirements can be supported automatically when a system’s model is modified, during (re-)configuration and at runtime.