diff --git a/configs/ci.nix b/configs/ci.nix
index d60c208..43db68b 100644
--- a/configs/ci.nix
+++ b/configs/ci.nix
@@ -54,7 +54,7 @@ with lib; {
       nix-serve = {
         package = pkgs.nix-serve.override {
           nix =
-            inputs.unstable.legacyPackages.x86_64-linux.nixVersions.nix_2_13;
+            inputs.unstable.legacyPackages.x86_64-linux.nixVersions.nix_2_12;
         };
         enable = true;
         secretKeyFile = config.sops.secrets.bin_cache_priv_key.path;