diff --git a/html/changelogs/AutoChangeLog-pr-13489.yml b/html/changelogs/AutoChangeLog-pr-13489.yml
new file mode 100644
index 0000000000..4780b3fadb
--- /dev/null
+++ b/html/changelogs/AutoChangeLog-pr-13489.yml
@@ -0,0 +1,4 @@
+author: "timothyteakettle"
+delete-after: True
+changes: 
+  - tweak: "the minimum brightness of mutant parts is now a define"