diff --git a/hosts/build02/configuration.nix b/hosts/build02/configuration.nix
index 7a29129..c6e5914 100644
--- a/hosts/build02/configuration.nix
+++ b/hosts/build02/configuration.nix
@@ -11,6 +11,8 @@
     inputs.self.nixosModules.disko-zfs
   ];
 
+  nixCommunity.gc.gbFree = 500;
+
   boot.kernelParams = [ "zfs.zfs_arc_max=${toString (24 * 1024 * 1024 * 1024)}" ]; # 24GB, try to limit OOM kills / reboots
 
   networking.hostName = "build02";
diff --git a/hosts/build03/configuration.nix b/hosts/build03/configuration.nix
index 02c76d2..9193726 100644
--- a/hosts/build03/configuration.nix
+++ b/hosts/build03/configuration.nix
@@ -17,6 +17,8 @@
     ./postgresql.nix
   ];
 
+  nixCommunity.gc.gbFree = 500;
+
   systemd.network.networks."10-uplink".networkConfig.Address = "2a01:4f9:3b:2946::1/64";
 
   networking.hostName = "build03";