diff --git a/rncryptor.cabal b/rncryptor.cabal
index 55d00c2..bd7c45c 100644
--- a/rncryptor.cabal
+++ b/rncryptor.cabal
@@ -1,5 +1,5 @@
 name:                rncryptor
-version:             0.3.0.2
+version:             0.3.0.3
 synopsis:            Haskell implementation of the RNCryptor file format
 description:         Pure Haskell implementation of the RNCrytor spec.
 license:             MIT
diff --git a/src/Crypto/RNCryptor/V3/Decrypt.hs b/src/Crypto/RNCryptor/V3/Decrypt.hs
index 946b765..22a975f 100644
--- a/src/Crypto/RNCryptor/V3/Decrypt.hs
+++ b/src/Crypto/RNCryptor/V3/Decrypt.hs
@@ -7,6 +7,7 @@ module Crypto.RNCryptor.V3.Decrypt
   , decryptStream
   ) where
 
+import           Control.Monad               (unless)
 import           Control.Monad.State
 import           Control.Exception           (throwIO)
 import           Crypto.Cipher.AES           (AES256)
diff --git a/stack-9.4.yaml b/stack-9.4.yaml
new file mode 100644
index 0000000..18554e2
--- /dev/null
+++ b/stack-9.4.yaml
@@ -0,0 +1,12 @@
+resolver: lts-21.20
+
+packages:
+- '.'
+
+flags:
+  rncryptor:
+    fastpbkdf2: false
+
+extra-deps:
+- bytestring-arbitrary-0.1.0
+- fastpbkdf2-0.1.0.0
diff --git a/stack.yaml b/stack.yaml
index 521e4a2..134cbc8 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,9 +1,13 @@
-resolver: lts-6.5
-install-ghc: true
-flags: {}
+# resolver: lts-21.20
+resolver: nightly-2023-11-15
+
 packages:
 - '.'
-system-ghc: false
+
+flags:
+  rncryptor:
+    fastpbkdf2: false
+
 extra-deps:
 - bytestring-arbitrary-0.1.0
 - fastpbkdf2-0.1.0.0