diff --git a/modules/default.nix b/modules/default.nix
index e22176d..9663205 100644
--- a/modules/default.nix
+++ b/modules/default.nix
@@ -100,7 +100,7 @@
       );
       # Add unstable channel
       packageOverrides = pkgs: {
-        unstable = import (builtins.fetchTarball "https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz") {
+        unstable = import (import ../nix/sources.nix).nixpkgs-unstable {
           config = config.nixpkgs.config;
         };
       };
diff --git a/nix/sources.json b/nix/sources.json
index 4310839..506462a 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -35,6 +35,18 @@
         "url": "https://github.com/NixOS/nixpkgs/archive/65c9cc79f1d179713c227bf447fb0dac384cdcda.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
+    "nixpkgs-unstable": {
+        "branch": "nixos-unstable",
+        "description": "Nix Packages collection",
+        "homepage": "",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "e9158eca70ae59e73fae23be5d13d3fa0cfc78b4",
+        "sha256": "0cnmvnvin9ixzl98fmlm3g17l6w95gifqfb3rfxs55c0wj2ddy53",
+        "type": "tarball",
+        "url": "https://github.com/nixos/nixpkgs/archive/e9158eca70ae59e73fae23be5d13d3fa0cfc78b4.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
     "pre-commit-hooks.nix": {
         "branch": "master",
         "description": "Seamless integration of https://pre-commit.com git hooks with Nix.",