diff --git a/pkgs/development/tools/misc/hydra/unstable.nix b/pkgs/development/tools/misc/hydra/unstable.nix
index 733966f47062..373f80a2f052 100644
--- a/pkgs/development/tools/misc/hydra/unstable.nix
+++ b/pkgs/development/tools/misc/hydra/unstable.nix
@@ -123,13 +123,13 @@ let
 in
 stdenv.mkDerivation rec {
   pname = "hydra";
-  version = "2023-11-17";
+  version = "2023-12-01";
 
   src = fetchFromGitHub {
     owner = "NixOS";
     repo = "hydra";
-    rev = "8f48e4ddecbf403be35f8243b97d73cb39dd61bb";
-    hash = "sha256-5q/7yz6jJedD8YU3SuYyXtN3qEAlOBRKGZxOcYt/0X8=";
+    rev = "4d1c8505120961f10897b8fe9a070d4e193c9a13";
+    hash = "sha256-vXTuE83GL15mgZHegbllVAsVdDFcWWSayPfZxTJN5ys=";
   };
 
   buildInputs = [
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index b4c539438a2d..f8dce5250fa0 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -22059,7 +22059,7 @@ with pkgs;
 
   hwloc = callPackage ../development/libraries/hwloc { };
 
-  hydra_unstable = callPackage ../development/tools/misc/hydra/unstable.nix { nix = nixVersions.nix_2_17; };
+  hydra_unstable = callPackage ../development/tools/misc/hydra/unstable.nix { nix = nixVersions.nix_2_18; };
 
   hydra-cli = callPackage ../development/tools/misc/hydra-cli { };