diff --git a/config/services/hydra/default.nix b/config/services/hydra/default.nix
index 4cff514..9d3bf28 100644
--- a/config/services/hydra/default.nix
+++ b/config/services/hydra/default.nix
@@ -16,6 +16,8 @@
     useSubstitutes = true;
     extraConfig = ''
       binary_cache_public_uri = https://cache.kyouma.net
+      evaluator_workers = 8
+      evaluator_max_memory_size = 4096
     '';
   };
   services.harmonia = {
diff --git a/config/services/hydra/nix-config.nix b/config/services/hydra/nix-config.nix
index 1458299..cb1f5b8 100644
--- a/config/services/hydra/nix-config.nix
+++ b/config/services/hydra/nix-config.nix
@@ -2,6 +2,7 @@
   nix.buildMachines = [
     {
       hostName = "localhost";
+      sshUser = "hydra-queue-runner";
       maxJobs = 40;
       speedFactor = 40;
       systems = [ "x86_64-linux" "x86_64-darwin" ];