diff --git a/modules/nixos/nix/default.nix b/modules/nixos/nix/default.nix
index 08ed962..1b80b72 100644
--- a/modules/nixos/nix/default.nix
+++ b/modules/nixos/nix/default.nix
@@ -29,5 +29,11 @@
     ];
   };
 
+  nix.gc = {
+    automatic = true;
+    options = "--delete-older-than 30d";
+    dates = "weekly";
+  };
+
   nixpkgs.hostPlatform = system;
 }