diff --git a/build01/configuration.nix b/build01/configuration.nix
index bee86a5..7be9a02 100644
--- a/build01/configuration.nix
+++ b/build01/configuration.nix
@@ -25,9 +25,6 @@
   networking.hostName = "build01";
   networking.hostId = "d2905767";
 
-  # Emulate armv7 until we have proper builders
-  boot.binfmt.emulatedSystems = [ "armv7l-linux" ];
-
   systemd.network.networks."10-uplink".networkConfig.Address = "2a01:4f8:13b:2ceb::1/64";
 
   system.stateVersion = "20.03";
diff --git a/roles/remote-builder/aarch64-build04.nix b/roles/remote-builder/aarch64-build04.nix
index d3c02ea..17e4c0e 100644
--- a/roles/remote-builder/aarch64-build04.nix
+++ b/roles/remote-builder/aarch64-build04.nix
@@ -5,6 +5,7 @@
     {
       hostName = "build04.nix-community.org";
       maxJobs = 4;
+      protocol = "ssh"; # this machine is used by hydra which doesn't support ssh-ng
       sshKey = config.sops.secrets.id_buildfarm.path;
       sshUser = "nix";
       system = "aarch64-linux";
diff --git a/roles/remote-builder/aarch64-nixos-community.nix b/roles/remote-builder/aarch64-nixos-community.nix
index 794e610..d3b3c53 100644
--- a/roles/remote-builder/aarch64-nixos-community.nix
+++ b/roles/remote-builder/aarch64-nixos-community.nix
@@ -5,6 +5,7 @@
     {
       hostName = "aarch64.nixos.community";
       maxJobs = 64;
+      protocol = "ssh-ng";
       sshKey = config.sops.secrets.aarch64_nixos_community.path;
       sshUser = "nixcommunity";
       system = "aarch64-linux";