Pre-service teachers' often suboptimal use of technology in teaching can be explained by low levels of technology acceptance. The present study aims to investigate how technology acceptance can be promoted. Based on the Technology Acceptance Model by Davis (1986), we hypothesized that encouraging pre-service teachers to constructively engage with rather than passively reading tool-related information should increase their assessments of the tool's perceived usefulness, perceived ease of use, intention to use and actual use in lesson plans. In an experimental study, N = 53 pre-service teachers were either asked to read a blog post about the potential of a mind mapping tool (passive condition) or to work on small tasks covering the same information as the blog post (constructive condition). Finally, all participants were instructed to develop lesson plans. Contrary to our hypothesis, analyses of variance showed that passive engagement had stronger positive effects on technology acceptance than constructive engagement, i.e., reading a blog post significantly increased pre-service teachers' perceived ease of use (partial[eta-squared] = 0.15) compared to working constructively on open-ended tasks (p < 0.01). Exploratory analyses indicated that deeper engagement with the tasks in the constructive condition was associated with lower technology acceptance (r = [-0.37; -0.27], p < 0.05). Nevertheless, both conditions yielded a significant increase in intention to use over time, indicating that engagement with information about a tool in general can foster pre-service teachers' technology acceptance.