diff --git a/doc/timeline/week24.txt b/doc/timeline/week24.txt
index a29973df5f0e7b1c3729d83a64d351724f7a6f9a..5cd623b66eedee56241d7648f530584849d86f0c 100644
--- a/doc/timeline/week24.txt
+++ b/doc/timeline/week24.txt
@@ -1,9 +1,11 @@
 Week 24 (08.06. - 14.06.)
 =========================
 
-[ ] mmt: upstream changes to importers s.t. we don't get faulty data
+[x] mmt: upstream changes to importers s.t. we don't get faulty data
     in the future
 
+    - https://github.com/UniFormal/MMT/pull/521
+
 [x] supervision directory: clean up, find reasonable nomenclature
 
     - use ulo-storage-* as a prefix for all stuff related to making