diff --git a/morph/lib/issuer-aws.nix b/morph/lib/issuer-aws.nix
index 86687a0fae88536fb0df080fe9aadf17def6450d..4a7b418610a9c25792abfd82b0156f2b66b53a0d 100644
--- a/morph/lib/issuer-aws.nix
+++ b/morph/lib/issuer-aws.nix
@@ -22,5 +22,6 @@
   nix.gc = {
     automatic = true;
     dates = "weekly";
+    options = "--delete-older-than 30d";
   };
 }