Fuzzy logic has been used yet for extending database models to deal with vagueness in the definitions of linguistic concepts as "tall" or "long". However, the extension of existing programming interfaces for fuzziness requires a proper modularization of the underlying concerns of numerical imprecision handling. Such modularization should not interfere with existing programming practices, and they should not obscure the original design. Aspect?oriented design (AOD) enables such form of non?intrusive extensions to be added to existing software libraries. In this paper, the main design and implementation issues of such AOD?based extensions on OJB database libraries are briefly sketched.