In this research we aim to reproduce and extend the positive results about the effect of humor in solving mathematical word problems. We examined whether solving humorous word problems has some effect on either word problems demanding realistic consideration or word problems of the well-known routine type. Fifth- and sixth-grade students (N=1,153) solved different types of tasks including humorous, routine and "problematic" word problems, answered further questions concerning their attitude towards mathematics. Our results suggest that while sixth-graders outperformed their fifth-grade peers, the positive effect of humorous word problems proved to be even more relevant than the school grade. However, there has been some possible negative effect of humor when solving routine word problems. Furthermore, students expressed a positive attitude toward humorous word problems by selecting these as their favorite tasks compared to other types of word problems. The results obtained provide further evidence on the desirability and feasibility of introducing (more) humor in mathematics education.