diff --git a/CHANGELOG.md b/CHANGELOG.md
index 79b48f5..4f3a1fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,3 +8,9 @@ __changed__
 
 __removed__
 - Removed explicit hex methods (use `toString('hex')` on the Buffer) (#104)
+
+# 2.3.1
+
+__breaking changes__
+
+9-letter mnemonics can no longer be geerated and calling `validateMnemonic` will always return false. This was [fixed in the BIP as a patch](https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki#generating-the-mnemonic), so we had to follow suite.