diff --git a/hosts/server7/configuration.nix b/hosts/server7/configuration.nix
index e319442d..7e6fdf30 100644
--- a/hosts/server7/configuration.nix
+++ b/hosts/server7/configuration.nix
@@ -52,15 +52,9 @@ in {
 
   nix = {
     package = pkgs.nixFlakes;
-    extraOptions = "experimental-features = nix-command flakes";
+    extraOptions = "experimental-features = nix-command flakes ca-references";
     gc.automatic = true;
     distributedBuilds = true;
-    buildMachines = [{
-      hostName = "hydra.hq.c3d2.de";
-      system = "x86_64-linux";
-      sshUser = "buildfarmer";
-      sshKey = "/root/.ssh/id_ed25519";
-    }];
   };
 
   virtualisation.docker.enable = true;