Security is an essential requirement for business processes. However, we observe that security is mostly addressed at the technical implementation level and not at the design level. In a previous work we motivated the need to address security already in business process modeling. In this paper, we show how one could use Aspect-Oriented Programming (AOP) to enforce security requirements in a modular way. Starting from a business process model where security requirements are expressed using a profile mechanism we generate As-pectJ [1] code, which enforces those requirements. This generation is based on a set of Model-to-Text transformation rules. As security is a typical example for crosscutting concerns the usage of aspects allows for a modular implementation, in which the implementation of the business process is separated from the implementation of the security properties.