diff --git a/src/api/server_server.rs b/src/api/server_server.rs
index af2015bb..67361f51 100644
--- a/src/api/server_server.rs
+++ b/src/api/server_server.rs
@@ -1595,6 +1595,12 @@ async fn create_join_event(
     )
     .map_err(|_| Error::BadRequest(ErrorKind::InvalidParam, "Origin field is invalid."))?;
 
+    services()
+        .rooms
+        .event_handler
+        .fetch_required_signing_keys([&value], &pub_key_map)
+        .await?;
+
     let mutex = Arc::clone(
         services()
             .globals