diff --git a/flake.lock b/flake.lock
index 326cb43..709ebb3 100644
--- a/flake.lock
+++ b/flake.lock
@@ -2,15 +2,16 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1619802032,
-        "narHash": "sha256-m0z6db6Q4rS+prCzrtcQovhFueNJ7pdtA8sPjayn32s=",
+        "lastModified": 1622056411,
+        "narHash": "sha256-+p/O18/b5URkcS7sZu8j3s+NCJSQVfP3BdcNxqWFqFo=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "0ae04ca063d61e462842fbfe16bcc55a10fdd6c2",
+        "rev": "169371366d6ca5aaee1dcfc1255bcd213766ca2a",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
+        "ref": "release-21.05",
         "repo": "nixpkgs",
         "type": "github"
       }
diff --git a/flake.nix b/flake.nix
index 83f8d2c..7f1cbc8 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,8 +2,7 @@
   description = "Zentralwerk network";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs";
-    # TODO: nixpkgs.url = "github:NixOS/nixpkgs/nixos-21.05";
+    nixpkgs.url = "github:NixOS/nixpkgs/release-21.05";
     # `nix flake update --override-flake zentralwerk-network-key git+file:///...`
     # to provide the GPG secret key
     zentralwerk-network-key.url = "git+https://gitea.c3d2.de/zentralwerk/network.git?dir=nix/key";