diff --git a/src/api/server/send_join.rs b/src/api/server/send_join.rs
index 461d5d58f..c29f5b2ec 100644
--- a/src/api/server/send_join.rs
+++ b/src/api/server/send_join.rs
@@ -71,7 +71,7 @@ async fn create_join_event(
 	let room_version_id = services.rooms.state.get_room_version(room_id).await?;
 
 	trace!("Generating event ID and converting to canonical json");
-	let Ok((event_id, value)) = gen_event_id_canonical_json(pdu, &room_version_id) else {
+	let Ok((event_id, mut value)) = gen_event_id_canonical_json(pdu, &room_version_id) else {
 		// Event could not be converted to canonical json
 		return Err!(Request(BadJson("Could not convert event to canonical json.")));
 	};
@@ -187,6 +187,13 @@ async fn create_join_event(
 				"Joining user did not pass restricted room's rules."
 			)));
 		}
+
+		services
+			.server_keys
+			.hash_and_sign_event(&mut value, &room_version_id)
+			.map_err(|e| {
+				err!(Request(InvalidParam(warn!("Failed to sign send_join event: {e}"))))
+			})?;
 	}
 
 	let mutex_lock = services