diff --git a/modules/os.nix b/modules/os.nix
index c1d5a86..5b49310 100644
--- a/modules/os.nix
+++ b/modules/os.nix
@@ -9,6 +9,7 @@
       dates = "weekly";
       automatic = true;
       randomizedDelaySec = "45min";
+      options = "--delete-older-than 30d";
     };
   };