diff --git a/courses/mathdata.md b/courses/mathdata.md
index 036772c9c30dbb5f640bf9b17f9b40d3a3452741..c475fe98f865915f3a2b1e59644c00cbb6be438a 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