diff --git a/systems/palatine-hill/hydra.nix b/systems/palatine-hill/hydra.nix
index d265715..16c270f 100644
--- a/systems/palatine-hill/hydra.nix
+++ b/systems/palatine-hill/hydra.nix
@@ -42,7 +42,12 @@ in
   services = {
     hydra = {
       enable = true;
-      package = inputs.hydra.packages.x86_64-linux.hydra;
+      package = inputs.hydra.packages.x86_64-linux.hydra.overrideAttrs (old: {
+        checkPhase = ''
+          export YATH_JOB_COUNT=8
+          ${old.checkPhase or "yath test"}
+        '';
+      });
       hydraURL = "https://hydra.alicehuston.xyz";
       smtpHost = "alicehuston.xyz";
       notificationSender = "hydra@alicehuston.xyz";