diff --git a/modules/system/nix.nix b/modules/system/nix.nix
index 64dbe8a..f32e2d8 100644
--- a/modules/system/nix.nix
+++ b/modules/system/nix.nix
@@ -1,16 +1,6 @@
 { config, lib, pkgs, ... }: {
   nix = rec {
-    # XXX: remove after upstream fixes https://github.com/NixOS/nix/issues/5728
-    package = pkgs.nixUnstable.overrideAttrs(_: rec {
-      version = "2.5${suffix}";
-      suffix = "pre20211007_${lib.substring 0 7 src.rev}";
-      src = pkgs.fetchFromGitHub {
-        owner = "NixOS";
-        repo = "nix";
-        rev = "844dd901a7debe8b03ec93a7f717b6c4038dc572";
-        sha256 = "sha256-fe1B4lXkS6/UfpO0rJHwLC06zhOPrdSh4s9PmQ1JgPo=";
-      };
-    });
+    package = pkgs.nixUnstable;
     binaryCaches = [
       "https://cache.nixos.org?priority=10"
       "https://lava.cachix.org"
diff --git a/overlays/default.nix b/overlays/default.nix
index 511e611..6e89c94 100644
--- a/overlays/default.nix
+++ b/overlays/default.nix
@@ -1,6 +1,7 @@
 builtins.map (path: import path) [
   ./discord.nix
   ./material-icons.nix
+  ./nix.nix
   ./picom.nix
   ./rofi.nix
   ./xinit.nix
diff --git a/overlays/nix.nix b/overlays/nix.nix
new file mode 100644
index 0000000..317f275
--- /dev/null
+++ b/overlays/nix.nix
@@ -0,0 +1,13 @@
+# TODO: remove after upstream fixes https://github.com/NixOS/nix/issues/5728
+self: super: {
+  nixUnstable = super.nixUnstable.overrideAttrs(_: rec {
+    version = "2.5${suffix}";
+    suffix = "pre20211007_${self.lib.substring 0 7 src.rev}";
+    src = self.fetchFromGitHub {
+      owner = "NixOS";
+      repo = "nix";
+      rev = "844dd901a7debe8b03ec93a7f717b6c4038dc572";
+      sha256 = "sha256-fe1B4lXkS6/UfpO0rJHwLC06zhOPrdSh4s9PmQ1JgPo=";
+    };
+  });
+}