diff --git a/CHANGELOG.md b/CHANGELOG.md
index f64ab9dea17745aa54dc4aee4ccbe4c2db1cba45..502634f90a19ef0418f9b1ff4f767ec21eea18b8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,12 @@ lemma.
   [discardable fraction](iris/algebra/dfrac.v) (`dfrac`) instead of a fraction
   (`frac`). Lemmas affected by this have been renamed such that the "frac" in
   their name has been changed into "dfrac". (by Simon Friis Vindum)
+* Equip `mono_nat` algebra with support for `dfrac`, make API more consistent,
+  and add notation for algebra elements. See `iris/algebra/lib/mono_nat.v` for
+  details. This affects some existing terms and lemmas:
+  - `mono_nat_auth` now takes a `dfrac`, but the recommendation is to port to the notation.
+  - `mono_nat_auth_frac_op`, `mono_nat_lb_op`: direction of equality is swapped.
+  - `mono_nat_auth_frac_valid`, `mono_nat_both_frac_valid`: use `dfrac` variant instead.
 
 **Changes in `bi`:**