Global textbooks, despite its popularity, have been criticized due to its prioritization of cognitive learning over the affective domain, leading to proposals for material adaptation through the use of humanized materials. This study explored the impact of humanized materials on learner interest in the English as a foreign language classroom compared to textbook activities. Sixteen non-English majored students at Nguyen Tat Thanh University took part in an Alternating Treatment Design experiment. Five humanized activities were developed from five chosen activities in Personal Best B1+ textbook and both types of activities were alternated systematically within and between classes. A six-point Likert scale survey was employed to gather data and statistical analysis was conducted. The results indicated that humanized activities consistently generated higher interest than textbook activities across three dimensions, namely affect, value, and knowledge. Furthermore, humanizing materials can enhance interest in both interesting and non-interesting materials.