--- a/rust/hedgewars-server/src/server/handlers/common.rs	Mon May 06 21:33:48 2019 +0200
+++ b/rust/hedgewars-server/src/server/handlers/common.rs	Mon May 06 22:57:49 2019 +0300
@@ -90,7 +90,9 @@
 
     response.add(LobbyJoined(all_nicks).send_self());
     for (flag, nicks) in &mut flag_selectors {
-        response.add(ClientFlags(add_flags(&[*flag]), replace(nicks, vec![])).send_self());
+        if !nicks.is_empty() {
+            response.add(ClientFlags(add_flags(&[*flag]), replace(nicks, vec![])).send_self());
+        }
     }
 
     response.add(server_msg.send_self());