diff --git a/src/core/pdu/mod.rs b/src/core/pdu/mod.rs
index 0c54812e..32ec19c6 100644
--- a/src/core/pdu/mod.rs
+++ b/src/core/pdu/mod.rs
@@ -116,7 +116,12 @@ impl PduEvent {
 			.map_or_else(|| Ok(BTreeMap::new()), |u| serde_json::from_str(u.get()))
 			.map_err(|_| Error::bad_database("Invalid unsigned in pdu event"))?;
 
-		unsigned.insert("age".to_owned(), to_raw_value(&1).unwrap());
+		// deliberately allowing for the possibility of negative age
+		let now: i128 = MilliSecondsSinceUnixEpoch::now().get().into();
+		let then: i128 = self.origin_server_ts.into();
+		let this_age: i128 = now.saturating_sub(then);
+
+		unsigned.insert("age".to_owned(), to_raw_value(&this_age).unwrap());
 		self.unsigned = Some(to_raw_value(&unsigned).expect("unsigned is valid"));
 
 		Ok(())