diff --git a/configuration.nix b/configuration.nix
index f230efe..213b359 100644
--- a/configuration.nix
+++ b/configuration.nix
@@ -65,4 +65,6 @@
   security.sudo.wheelNeedsPassword = false;
 
   system.autoUpgrade.enable = true;
+  nix.gc.automatic = true;
+  nix.gc.options = "--delete-older-than 15d";
 }