diff --git a/hosts/nixos/nfss/system.nix b/hosts/nixos/nfss/system.nix
index e8bebac..abcbbbd 100644
--- a/hosts/nixos/nfss/system.nix
+++ b/hosts/nixos/nfss/system.nix
@@ -21,6 +21,13 @@
     efiSupport = true;
     efiInstallAsRemovable = true;
     zfsSupport = true;
+    configurationLimit = 10;
+  };
+
+  nix.gc = {
+    automatic = true;
+    dates = "monthly";
+    options = "--delete-older-than 30d";
   };
 
   # Disable systemd stage-1 (use traditional initrd for ZFS compatibility)
diff --git a/hosts/nixos/thinkpad/system.nix b/hosts/nixos/thinkpad/system.nix
index 8542b7c..6a93fbc 100644
--- a/hosts/nixos/thinkpad/system.nix
+++ b/hosts/nixos/thinkpad/system.nix
@@ -16,6 +16,13 @@
     systemd-boot.configurationLimit = 50;
     efi.canTouchEfiVariables = true;
     timeout = 3;
+    configurationLimit = 10;
+  };
+
+  nix.gc = {
+    automatic = true;
+    dates = "monthly";
+    options = "--delete-older-than 30d";
   };
 
   # Use latest kernel for better hardware support