diff --git a/maintenance.md b/maintenance.md
index 9c0aa7f..dc69e5f 100644
--- a/maintenance.md
+++ b/maintenance.md
@@ -21,3 +21,4 @@ Newest entries at the bottom.
 - 2026-09-14: Water recycling filters replaced.
 - 2026-09-15: Airlock seals checked.
 - 2026-09-15: Water recycling filters replaced.
+- 2026-09-16: Coffee machine descaled.