diff --git a/keyfork-derive-openpgp/src/main.rs b/keyfork-derive-openpgp/src/main.rs
index c7d8a2c..e25bda1 100644
--- a/keyfork-derive-openpgp/src/main.rs
+++ b/keyfork-derive-openpgp/src/main.rs
@@ -137,6 +137,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let cert =
         Cert::from_packets(vec![Packet::SecretKey(primary_key.clone())].into_iter()).unwrap();
     let builder = SignatureBuilder::new(SignatureType::PositiveCertification)
+        .set_key_validity_period(one_day.duration_since(epoch)?)?
         .set_signature_creation_time(epoch)?
         .set_key_flags(subkey_format[0].inner().clone())?;
     let binding = default_userid.bind(&mut primary_key.clone().into_keypair()?, &cert, builder)?;