diff --git a/modules/nix/linux-builder.nix b/modules/nix/linux-builder.nix
index 67284b24..9edfed6c 100644
--- a/modules/nix/linux-builder.nix
+++ b/modules/nix/linux-builder.nix
@@ -192,9 +192,11 @@ in
 
     environment.etc."ssh/ssh_config.d/100-linux-builder.conf".text = ''
       Host linux-builder
+        User builder
         Hostname localhost
         HostKeyAlias linux-builder
         Port 31022
+        IdentityFile /etc/nix/builder_ed25519
     '';
 
     nix.distributedBuilds = true;