I am a professor in the Federal Institute of Alagoas, interested in configurable systems with a high amount of variablity. Currently, I'm investigating approaches to safely evolve configurable systems that are statically configurable with the C preprocessor. Our approach considers perfective evolution, which focuses on improving software quality by performing refactorings, and defective evolution, which focuses on detecting existing configuration-related bugs, including memory leaks, resource leaks, syntax errors, and type errors. Configuration-related bugs appear only when we enable or disable certain compile-time configuration options.