Fake news and disinformation are easily spread in today's digital society. Therefore, it is important that students learn how to evaluate the trustworthiness of online information, but this skill is often confined to a limited number of subjects in secondary education. History classes can potentially contribute to developing this skill. Therefore, the first aim of this study was to investigate whether there is a relationship between how Grade 9 students (N = 112) perform while evaluating the trustworthiness of historical sources and internet sources. Average student performance on both kinds of sources was similar, but the distribution of the scores was significantly different. There was a moderate correlation between students' total scores on the historical task and the internet task. Two of the three criteria of trustworthiness that could be used on both kinds of sources were used by a great majority in both tasks. The second aim was to gain more insight into students' (N = 8) and teachers' perspectives (N = 8) on the usefulness of the evaluation skill learned in history class for other contexts, especially when searching on the internet. While most of the teachers mentioned the importance of the skill when using the internet, none of the students did so spontaneously. We suggest that history classrooms are an appropriate place to teach students not only about historical sources but also about internet sources, provided that more explicit attention is given to the relationship between both types of sources.