diff --git a/flake.nix b/flake.nix
index c052759..e217082 100644
--- a/flake.nix
+++ b/flake.nix
@@ -158,7 +158,13 @@
 
           bagel.monitoring.grafana-agent.tenant = "lix";
           bagel.secrets.tenant = "lix";
-          bagel.builders.extra-build-capacity.provider.tenant = "lix";
+          bagel.builders.extra-build-capacity.provider = {
+            tenant = "lix";
+            buildfarmPublicKeys = [
+              # buildbot.lix.systems SSH key
+              "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIDu4cEqZzAI/1vZjSQkTJ4ijIg9nuloOuSKUrnkJIOFn"
+            ];
+          };
         }
       ];