diff --git a/modules/gpg.nix b/modules/gpg.nix
index aee6ee3..8abdc58 100644
--- a/modules/gpg.nix
+++ b/modules/gpg.nix
@@ -7,6 +7,13 @@
       enableSshSupport = true;
       sshKeys = ["A0B5D579ECACC45C51B2B38E317D346182083CD8"];
 
+      # The amount of time a key is kept in the cache before it is removed.
+      # The timer is reset after each use within that window.
+      defaultCacheTtl = 86400; # 1 Day
+      defaultCacheTtlSsh = 86400; # 1 Day
+
+      # The maximum amount after which the passphrase has to be retyped,
+      # even if the key is still cached.
       maxCacheTtl = 86400; # 1 Day
       maxCacheTtlSsh = 86400; # 1 Day
     };