diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+1.2.1.0 [2024-03-16]
+--------------------
+* Add Mini.Transformers.ReaderT.local
+
 1.2.0.0 [2024-03-15]
 --------------------
 * Mini.Transformers.ParserT:
diff --git a/Mini/Transformers/ReaderT.hs b/Mini/Transformers/ReaderT.hs
--- a/Mini/Transformers/ReaderT.hs
+++ b/Mini/Transformers/ReaderT.hs
@@ -10,6 +10,7 @@
 
   -- * Operations
   ask,
+  local,
 ) where
 
 import Control.Applicative (
@@ -62,3 +63,7 @@
 -- | Fetch the read-only environment
 ask :: (Monad m) => ReaderT r m r
 ask = ReaderT pure
+
+-- | Run a computation in a modified environment
+local :: (r -> r') -> ReaderT r' m a -> ReaderT r m a
+local f m = ReaderT $ runReaderT m . f
diff --git a/mini.cabal b/mini.cabal
--- a/mini.cabal
+++ b/mini.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.4
 name:               mini
-version:            1.2.0.0
+version:            1.2.1.0
 license:            MIT
 license-file:       LICENSE
 copyright:          (c) 2023-2024 Victor Wallsten