diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,8 @@
 # Changelog
 
+- 0.2.1 (2025-12-28)
+  * Adds an 'llvm' build flag and tests with GHC 9.10.3.
+
 - 0.2.0 (2025-06-21)
   * The 'derive' function is now total, returning 'Nothing' when supplied
     with bad inputs.
diff --git a/ppad-pbkdf.cabal b/ppad-pbkdf.cabal
--- a/ppad-pbkdf.cabal
+++ b/ppad-pbkdf.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               ppad-pbkdf
-version:            0.2.0
+version:            0.2.1
 synopsis:           A password-based key derivation function
 license:            MIT
 license-file:       LICENSE
@@ -8,12 +8,17 @@
 maintainer:         jared@ppad.tech
 category:           Cryptography
 build-type:         Simple
-tested-with:        GHC == { 9.8.1 }
+tested-with:        GHC == 9.10.3
 extra-doc-files:    CHANGELOG
 description:
   A pure implementation of the password-based key derivation function PBKDF2,
   per RFC 2898.
 
+flag llvm
+  description: Use GHC's LLVM backend.
+  default:     False
+  manual:      True
+
 source-repository head
   type:     git
   location: git.ppad.tech/pbkdf.git
@@ -23,6 +28,8 @@
   hs-source-dirs:   lib
   ghc-options:
       -Wall
+  if flag(llvm)
+    ghc-options: -fllvm -O2
   exposed-modules:
       Crypto.KDF.PBKDF
   build-depends: