diff --git a/changes/log_heartbeat_test b/changes/log_heartbeat_test
index f0d143b6de..7db97ed03c 100644
--- a/changes/log_heartbeat_test
+++ b/changes/log_heartbeat_test
@@ -3,3 +3,4 @@
       with non-integer offsets. Instead of comparing the end of the
       time string against a constant, compare it to the output of
       format_local_iso_time when given the correct input.
+      Fixes bug 18039.