diff --git a/flake.nix b/flake.nix
index 7e9ef01..6ff7998 100644
--- a/flake.nix
+++ b/flake.nix
@@ -24,9 +24,7 @@
                   qemu,
                 }:
                 haskell-nix.hix.project {
-                  compiler-nix-name = "ghc948";
-                  # This works
-                  #compiler-nix-name = "ghc966";
+                  compiler-nix-name = "ghc966";
                   src = builtins.path {
                     path = ./.;
                     name = "riscv-formal-source";