diff --git a/services/hydra-core.nix b/services/hydra-core.nix
index 0197c87..a145991 100644
--- a/services/hydra-core.nix
+++ b/services/hydra-core.nix
@@ -62,6 +62,8 @@ mkIf cfg.hydra-core {
     #package = hydra-src-pkg ;
   };
 
+  systemd.services.hydra-evaluator.serviceConfig.Nice = -19;
+
   #systemd.services.hydra-evaluator = {
   #  path = [ pkgs.nettools config.services.hydra.package ];
   #};