diff --git a/changelog.md b/changelog.md
index aca6820ae87..078c9ea8b86 100644
--- a/changelog.md
+++ b/changelog.md
@@ -48,6 +48,7 @@
  ### Lua API
    * Accessing wesnoth.theme_items.unit_status no longer prevents the unit
      status (poisoned/slowed/etc) from being shown in the sidebar. (Issue#4079)
+   * side.flag is now writable. `wesnoth.set_side_id` remains supported. (Issue#4396)
  ### WML engine
    * Ranges can now have upper limit "infinity" instead of using a big number like "99" or "99999"
    * Print a deprecation warning for `[terrain_type]`'s partly-implemented `vision_alias`