Proper mathematical skills are important for every science course and mathematics-intensive chemistry courses rely on a sound mathematical pre-knowledge. In the first-year quantum chemistry course at this university, it was noticed that many students lack basic mathematical knowledge. To tackle the mathematics problem, a remedial mathematics program was set up. Each week students were provided online assignments that would prepare them for the upcoming quantum chemistry lecture. This should also facilitate the needed mathematical transfer from calculus to quantum chemistry. The lecturer closely monitored the progress of the students and gave feedback. The mathematical skills of the students improved as a result of the remedial mathematics program. Students could better follow the quantum chemistry lectures than previous years and they were more involved during the course. Unfortunately, the percentage of students passing the quantum chemistry exam did not change substantially. The following year adjustments were made to the remedial program and the quantum chemistry course, resulting in better grades. Proper mathematical skills appear to be indispensable, but are not sufficient for understanding quantum chemistry. (Contains 4 figures, 2 tables, and 1 note.)