diff --git a/CHANGES.md b/CHANGES.md
index 4a2dd37a6..6d80d9f4d 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -5,6 +5,11 @@
 ### Build
 * use OCaml 4.08.1 as the minimal supported version (PR #803)
 
+## v2.5.1
+
+### Bug fixes
+* fix a critical unsoundness bug with bvnot primitive (#819)
+
 ## v2.5.0
 
 ### New features