diff --git a/flake.nix b/flake.nix
index e414d26..f9f78de 100644
--- a/flake.nix
+++ b/flake.nix
@@ -24,8 +24,8 @@
 
         stdenv =
           if pkgs.hostPlatform.isLinux
-          then pkgs.stdenvAdapters.useMoldLinker pkgs.llvmPackages_19.libcxxStdenv
-          else pkgs.llvmPackages_19.libcxxStdenv;
+          then pkgs.stdenvAdapters.useMoldLinker pkgs.llvmPackages_18.libcxxStdenv
+          else pkgs.llvmPackages_18.libcxxStdenv;
 
         sources = import ./_sources/generated.nix {
           inherit (pkgs) fetchFromGitHub fetchgit fetchurl dockerTools;
@@ -89,7 +89,7 @@
 
               clang-format = {
                 enable = true;
-                package = pkgs.llvmPackages_19.clang-tools;
+                package = pkgs.llvmPackages_18.clang-tools;
               };
             };
           };
@@ -99,9 +99,10 @@
               [
                 alejandra
                 bear
-                (llvmPackages_19.clang-tools.override {enableLibcxx = true;})
+                (llvmPackages_18.clang-tools.override {enableLibcxx = true;})
                 lldb
                 meson
+                nil
                 ninja
                 nvfetcher
                 pkg-config
@@ -126,7 +127,7 @@
               in "${linuxPackages_latest.nvidia_x11}/share/vulkan/icd.d/nvidia_icd.x86_64.json:${vulkanPaths}";
 
             shellHook = ''
-              export PATH="${llvmPackages_19.clang-tools.override {enableLibcxx = true;}}/bin:$PATH"
+              export PATH="${llvmPackages_18.clang-tools.override {enableLibcxx = true;}}/bin:$PATH"
             '';
 
             name = "C++";