Educators encounter challenges in performing materials adaptation stemming from time limitations, institutional responsibilities, administrative demands, and a dearth of formal training in materials development resulting in improper adaptation and ineffective learning activities. This research investigated the process of adapting materials as a qualitative case study. The data were gathered from a senior high school teacher in Banda Aceh, Indonesia, by means of document analysis (e.g., teaching materials), observation, and interview. The results revealed that the instructor frequently added and modified educational resources to facilitate learning through several modalities. The act of deleting, simplifying, and rearranging was occasionally performed. Nevertheless, students' reflection on course contents, inadequate level of difficulty, demanding tasks, and excessive reliance on first language remained as issues. This study emphasizes the role of adaptation in promoting meaningful learning experiences and urges the integration of culturally relevant themes with a variety of learning activities. Educators can use these findings to support professional developments focused on effective material adaption tactics, allowing them to reflect on their existing methods, try new approaches, and interact with colleagues to share successful practices.