diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..1d953f4
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use nix
diff --git a/shell.nix b/shell.nix
index d0dd510..d67a849 100644
--- a/shell.nix
+++ b/shell.nix
@@ -11,7 +11,7 @@ pkgs.mkShell rec {
   packages =
     with pkgs;
     [
-      haskell.packages.ghc9102.ghc
+      haskell.packages.ghc912.ghc
       zlib
     ]
     ++ map haskell.lib.justStaticExecutables [