diff --git a/debian/changelog b/debian/changelog
index b9917d77..2565feb9 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -9,7 +9,7 @@ livecd-rootfs (2.408.19) UNRELEASED; urgency=medium
   * Improve teardown_mountpoint to recursively find all submounts and
     unmount them, instead of working from a hard-coded list.  This makes
     the code resilient against other submounts being added later, including
-    downstream.
+    downstream.  LP: #1721279.
   * Also nuke the sleep / udevadm settle calls in the process, which should
     never be required and slow down the builds.
   * Begin adding support for a project-independent 'minimized' subproject,