diff --git a/modules/aggregator2/docs/aggregator2.txt b/modules/aggregator2/docs/aggregator2.txt
index 75f29f9af521f7f4de10c2f52ea7d1a0999a44f4..3e499ceccf0cc70c07604626043127d0ec91549a 100644
--- a/modules/aggregator2/docs/aggregator2.txt
+++ b/modules/aggregator2/docs/aggregator2.txt
@@ -55,7 +55,8 @@ The aggregator can be configured with the following options:
 
 `sign.privatekey`
 :   The private key that should be used to sign the metadata, in PEM format.
-    The path to the private key can be absolute, or it can be relative to the `cert`-directory.
+    The path to the private key can be absolute, or it can be relative to the `cert`-directory. Skip this option or
+    set it to NULL if you don't want to sign the generated metadata.
 
 `sign.privatekey_pass`
 :   The password for the private key.