diff --git a/nix-tools/cabal.project b/nix-tools/cabal.project
index b96576a97a..e960f8a0a1 100644
--- a/nix-tools/cabal.project
+++ b/nix-tools/cabal.project
@@ -1,4 +1,4 @@
-index-state: 2024-12-11T00:00:00Z
+index-state: 2024-12-10T00:00:00Z
 
 packages: nix-tools
 
diff --git a/nix-tools/static/project.nix b/nix-tools/static/project.nix
index e7ed7832e7..c494d320d8 100644
--- a/nix-tools/static/project.nix
+++ b/nix-tools/static/project.nix
@@ -64,7 +64,7 @@ let
 
   static-nix-tools-project = pkgs.haskell-nix.project' {
 
-    compiler-nix-name = "ghc928";
+    compiler-nix-name = "ghc966";
 
     src = ../.;