diff --git a/riichi-scoring.cabal b/riichi-scoring.cabal
--- a/riichi-scoring.cabal
+++ b/riichi-scoring.cabal
@@ -20,7 +20,7 @@
 -- PVP summary:     +-+------- breaking API changes
 --                  | | +----- non-breaking API additions
 --                  | | | +--- code changes with no API change
-version: 0.1.0.0
+version: 0.1.0.1
 -- A short (one-line) description of the package.
 synopsis: A CLI tool for interpreting and scoring Riichi Mahjong hands.
 -- A longer description of the package.
@@ -63,11 +63,11 @@
 
   hs-source-dirs: src
   build-depends:
-    base ^>=4.20.2.0,
+    base ^>=4.19.2.0,
     containers >=0.7 && <0.8,
     mtl >=2.3.1 && <2.4,
 
-  default-language: GHC2024
+  default-language: GHC2021
 
 executable riichi
   -- Import common warning flags.
@@ -80,7 +80,7 @@
   -- other-extensions:
   -- Other library packages from which modules are imported.
   build-depends:
-    base ^>=4.20.2.0,
+    base ^>=4.19.2.0,
     containers >=0.7 && <0.8,
     mtl >=2.3.1 && <2.4,
     riichi-scoring,
@@ -88,4 +88,4 @@
   -- Directories containing source files.
   hs-source-dirs: app
   -- Base language which the package is written in.
-  default-language: GHC2024
+  default-language: GHC2021