diff --git a/flake.lock b/flake.lock
index f6f514a..6a63fc0 100644
--- a/flake.lock
+++ b/flake.lock
@@ -2,16 +2,18 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1782233679,
-        "narHash": "sha256-QyuGP5+QOtmXpy4i2X4DhBVBaySBdDKQEhqKcphcp34=",
-        "rev": "667d5cf1c59585031d743c78b394b0a647537c35",
-        "revCount": 1007414,
-        "type": "tarball",
-        "url": "https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.2605.1007414%2Brev-667d5cf1c59585031d743c78b394b0a647537c35/019f0001-c3e4-7132-bec5-e3972fb9ab0a/source.tar.gz"
+        "lastModified": 1782375420,
+        "narHash": "sha256-wiPYmEuHbJvleW489n6+lamL7JSJg3pcKUYwURU9CkI=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4062d36ebeae843c750011eef6b61ec9a9dbc9a9",
+        "type": "github"
       },
       "original": {
-        "type": "tarball",
-        "url": "https://flakehub.com/f/NixOS/nixpkgs/0"
+        "owner": "NixOS",
+        "ref": "nixos-26.05",
+        "repo": "nixpkgs",
+        "type": "github"
       }
     },
     "pyproject-build-systems": {
diff --git a/flake.nix b/flake.nix
index a017e5d..cb44f23 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,7 +2,7 @@
   description = "Tartarus: a Nix-defined containment runtime for auditable agents";
 
   inputs = {
-    nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-26.05";
 
     # uv2nix turns uv.lock into a Nix Python package set, so the harness's Python
     # deps are resolved from the lockfile rather than hand-maintained.