diff --git a/nix/sources.json b/nix/sources.json
index 1aeba5c..f944204 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -54,10 +54,22 @@
         "homepage": "https://github.com/NixOS/nixpkgs",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "cf59fbd539681f5ec2f4a82cf77aae7ab827a03f",
-        "sha256": "03h5k850x6g44b1101yzkmzb0lyln48y488lsrya77502wjzp68j",
+        "rev": "63ee5cd99a2e193d5e4c879feb9683ddec23fa03",
+        "sha256": "0avbsx5chbwr0y55shndkzf0ixx3bznbzq526p5nj8llryxa10af",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/cf59fbd539681f5ec2f4a82cf77aae7ab827a03f.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs/archive/63ee5cd99a2e193d5e4c879feb9683ddec23fa03.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
+    "nixpkgsUnstable": {
+        "branch": "nixos-unstable",
+        "description": "Nix Packages collection",
+        "homepage": "",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "c6c4a3d45ab200f17805d2d86a1ff1cc7ca2b186",
+        "sha256": "1f6q98vx3sqxcn6qp5vpy00223r9hy93w9pxq65h9gdwzy3w4qxv",
+        "type": "tarball",
+        "url": "https://github.com/nixos/nixpkgs/archive/c6c4a3d45ab200f17805d2d86a1ff1cc7ca2b186.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }