diff --git a/system/hosts/nixserver/home.nix b/system/hosts/nixserver/home.nix
index ec04b83..38682f8 100644
--- a/system/hosts/nixserver/home.nix
+++ b/system/hosts/nixserver/home.nix
@@ -128,8 +128,12 @@ in {
     }
   ];
   # limit CI CPU usage since I'm running everything else off this server too
-  systemd.services.nix-daemon.serviceConfig.CPUQuota = "50%";
-  systemd.services.hydra-evaluator.serviceConfig.CPUQuota = "50%";
+  systemd.services.nix-daemon.serviceConfig.CPUQuota = "100%";
+  nix.daemonCPUSchedPolicy = "idle";
+  nix.daemonIOSchedClass = "idle";
+  systemd.services.hydra-evaluator.serviceConfig.CPUQuota = "100%";
+  systemd.services.hydra-evaluator.serviceConfig.CPUSchedulingPolicy = "idle";
+  systemd.services.hydra-evaluator.serviceConfig.IOSchedulingClass = "idle";
   programs.ccache.enable = true;
 
   services.nginx.statusPage = true;
diff --git a/system/modules/common.nix b/system/modules/common.nix
index b7e884b..8341119 100644
--- a/system/modules/common.nix
+++ b/system/modules/common.nix
@@ -96,7 +96,8 @@
     # definitely don't need on minimal machines
     documentation.doc.enable = lib.mkIf cfg.minimal (lib.mkDefault false);
     programs.fish.enable = true;
-    users.defaultUserShell = lib.mkDefault pkgs.fish;
+    # conflicts with bash module's mkDefault
+    users.defaultUserShell = lib.mkOverride 999 pkgs.fish;
     users.users.${cfg.mainUsername} = {
       uid = 1000;
       isNormalUser = true;