diff --git a/nix/os/devices/srv0.home-ch.stefanjunker.de/hw.nix b/nix/os/devices/srv0.home-ch.stefanjunker.de/hw.nix
index 4714d6e..902519b 100644
--- a/nix/os/devices/srv0.home-ch.stefanjunker.de/hw.nix
+++ b/nix/os/devices/srv0.home-ch.stefanjunker.de/hw.nix
@@ -4,7 +4,6 @@ let
   stage1Modules =  [
     "aesni_intel"
     "kvm-intel"
-    "aes_x86_64"
 
     "virtio_balloon"
     "virtio_scsi"
diff --git a/nix/os/devices/srv0.home-ch.stefanjunker.de/versions.nix b/nix/os/devices/srv0.home-ch.stefanjunker.de/versions.nix
index 33e8f1a..f29fb73 100644
--- a/nix/os/devices/srv0.home-ch.stefanjunker.de/versions.nix
+++ b/nix/os/devices/srv0.home-ch.stefanjunker.de/versions.nix
@@ -1,14 +1,19 @@
 let
   nixpkgs = {
     url = "https://github.com/NixOS/nixpkgs/";
-    ref = "nixos-20.09";
-    rev = "ac60476ed94fd5424d9f3410c438825f793a8cbb";
+    ref = "nixos-21.05";
+    rev = "a1007637cea374bd1bafd754cfd5388894c49129";
   };
 in
 
 {
   inherit nixpkgs;
   "channels-nixos-stable" = nixpkgs;
+  "channels-nixos-21.05" = {
+    url = "https://github.com/NixOS/nixpkgs/";
+    ref = "nixos-21.05";
+    rev = "a1007637cea374bd1bafd754cfd5388894c49129";
+  };
   "channels-nixos-20.03" = {
     url = "https://github.com/NixOS/nixpkgs/";
     ref = "nixos-20.03";
@@ -22,16 +27,16 @@ in
   "channels-nixos-unstable" = {
     url = "https://github.com/NixOS/nixpkgs/";
     ref = "nixos-unstable";
-    rev = "900115a4f7fdd9189e7803ca781a65be663f2c89";
+    rev = "253aecf69ed7595aaefabde779aa6449195bebb7";
   };
   "nixpkgs-master" = {
     url = "https://github.com/NixOS/nixpkgs/";
     ref = "master";
-    rev = "f0fa05742058fef85c49e132c2851940915698ef";
+    rev = "200f2a7c58ed6b40b618377288c071314875fcd3";
   };
   "home-manager-module" = {
     url = "https://github.com/nix-community/home-manager";
-    ref = "release-20.09";
-    rev = "2aa20ae969f2597c4df10a094440a66e9d7f8c86";
+    ref = "release-21.05";
+    rev = "b39647e52ed3c0b989e9d5c965e598ae4c38d7ef";
   };
 }
diff --git a/nix/os/devices/srv0.home-ch.stefanjunker.de/versions.tmpl.nix b/nix/os/devices/srv0.home-ch.stefanjunker.de/versions.tmpl.nix
index a19cc09..e5c77de 100644
--- a/nix/os/devices/srv0.home-ch.stefanjunker.de/versions.tmpl.nix
+++ b/nix/os/devices/srv0.home-ch.stefanjunker.de/versions.tmpl.nix
@@ -1,14 +1,19 @@
 let
   nixpkgs = {
     url = "https://github.com/NixOS/nixpkgs/";
-    ref = "nixos-20.09";
-    rev = "<% git ls-remote https://github.com/nixos/nixpkgs nixos-20.09 | awk '{ print $1 }' | tr -d '\n' -%>";
+    ref = "nixos-21.05";
+    rev = "<% git ls-remote https://github.com/nixos/nixpkgs nixos-21.05 | awk '{ print $1 }' | tr -d '\n' -%>";
   };
 in
 
 {
   inherit nixpkgs;
   "channels-nixos-stable" = nixpkgs;
+  "channels-nixos-21.05" = {
+    url = "https://github.com/NixOS/nixpkgs/";
+    ref = "nixos-21.05";
+    rev = "<% git ls-remote https://github.com/nixos/nixpkgs nixos-21.05 | awk '{ print $1 }' | tr -d '\n' -%>";
+  };
   "channels-nixos-20.03" = {
     url = "https://github.com/NixOS/nixpkgs/";
     ref = "nixos-20.03";
@@ -31,7 +36,7 @@ in
   };
   "home-manager-module" = {
     url = "https://github.com/nix-community/home-manager";
-    ref = "release-20.09";
-    rev = "<% git ls-remote https://github.com/nix-community/home-manager.git release-20.09 | awk '{ print $1 }' | tr -d '\n' -%>";
+    ref = "release-21.05";
+    rev = "<% git ls-remote https://github.com/nix-community/home-manager.git release-21.05 | awk '{ print $1 }' | tr -d '\n' -%>";
   };
 }
diff --git a/nix/os/modules/ddclient-ovh.nix b/nix/os/modules/ddclient-ovh.nix
index f7f9893..3ee205c 100644
--- a/nix/os/modules/ddclient-ovh.nix
+++ b/nix/os/modules/ddclient-ovh.nix
@@ -23,7 +23,7 @@ in {
         server = "www.ovh.com";
         ssl = true;
         domains = [ cfg.domain ];
-        use = "web, web=ifconfig.co";
+        use = "web";
         inherit (passwords.dyndns.${cfg.domain}) username password;
     };
   };