diff --git a/io-classes-mtl/CHANGELOG.md b/io-classes-mtl/CHANGELOG.md
index 1403f92e..290aa4a7 100644
--- a/io-classes-mtl/CHANGELOG.md
+++ b/io-classes-mtl/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Revision history for io-classes-mtl
 
+## 0.1.2.1
+
+### Non breaking changes
+
+* Added `newArray` to `MArray ContTSTM` instance  (all GHC versions `9.10` were
+  affected).
+
 ## 0.1.2.0
 
 ### Non breaking changes
diff --git a/io-classes-mtl/io-classes-mtl.cabal b/io-classes-mtl/io-classes-mtl.cabal
index 357c8660..a160fd37 100644
--- a/io-classes-mtl/io-classes-mtl.cabal
+++ b/io-classes-mtl/io-classes-mtl.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               io-classes-mtl
-version:            0.1.2.0
+version:            0.1.2.1
 synopsis:           Experimental MTL instances for io-classes
 description:
     MTL instances for