diff --git a/krops.nix b/krops.nix
index 30399369..124ee6d4 100644
--- a/krops.nix
+++ b/krops.nix
@@ -5,11 +5,11 @@ let
   lib = import "${krops}/lib";
   pkgs = import "${krops}/pkgs" {};
 
-  hostSource = path:
+  hostSource = path: nixos-branch:
     lib.evalSource [ {
       nixpkgs.git = {
-        ref = "origin/nixos-20.03";
-        url = "https://github.com/NixOS/nixpkgs-channels.git";
+        ref = "origin/${nixos-branch}";
+        url = "https://github.com/NixOS/nixpkgs.git";
       };
       nixpkgs-unstable.git = {
         ref = "origin/master";
@@ -24,7 +24,7 @@ let
 
   deployContainer = containerName: host:
     pkgs.krops.writeDeploy containerName {
-      source = hostSource "containers/${containerName}";
+      source = hostSource "containers/${containerName}" "nixos-20.09";
       target = "root@${host}";
     };
 in {
@@ -34,13 +34,13 @@ in {
   kibana = deployContainer "kibana" "172.20.73.44";
 
   glotzbert = pkgs.krops.writeDeploy "glotzbert" {
-    source = hostSource "glotzbert";
+    source = hostSource "glotzbert" "nixos-20.09";
     target = lib.mkTarget "k-ot@glotzbert.hq.c3d2.de" // {
       sudo = true;
     };
   };
   pulsebert = pkgs.krops.writeDeploy "pulsebert" {
-    source = hostSource "pulsebert";
+    source = hostSource "pulsebert" "nixos-unstable";
     target = lib.mkTarget "k-ot@pulsebert.hq.c3d2.de" // {
       sudo = true;
     };