diff --git a/courses/mathdata.md b/courses/mathdata.md
index 51eb99d043b845dbce42a9dc14fb3c97e26c39f6..3bd64edd731e40a93a131e962663fc64e8a5b3c0 100644
--- a/courses/mathdata.md
+++ b/courses/mathdata.md
@@ -19,9 +19,9 @@ time for discussion.
 
 Announcements will be posted on the [KWARC mathematical data mailing list](http://lists.informatik.uni-erlangen.de/mailman/listinfo/math-data).
 
-## Upcoming seminars:
+### Upcoming seminars:
 
-#### An overview of mathematical data (Welcome to the seminar)
+##### An overview of mathematical data (Welcome to the seminar)
 
 - *Time*: Friday, May 8, 2020 from 14:00 to 15:30 (Central European Summer Time, UTC+2)
 - *Location*: online at Zoom ID: 995-5145-1656