diff --git a/system/nix.nix b/system/nix.nix
index 7354501..3ab9094 100644
--- a/system/nix.nix
+++ b/system/nix.nix
@@ -3,6 +3,7 @@
   nix = {
     gc = {
       automatic = true;
+      options = "--delete-older-than 14d";
     };
 
     optimise = {