diff -r add191d825f4 -r f5d43f007970 rust/hedgewars-server/src/server/handlers.rs
--- a/rust/hedgewars-server/src/server/handlers.rs	Fri Apr 12 22:36:54 2019 +0300
+++ b/rust/hedgewars-server/src/server/handlers.rs	Fri Apr 12 23:16:44 2019 +0300
@@ -207,7 +207,7 @@
                         response.remove_client(client_id);
                     }
                 }
-            } else {
+            } else if server.clients.contains(client_id) {
                 match message {
                     HWProtocolMessage::Quit(Some(msg)) => {
                         common::remove_client(server, response, "User quit: ".to_string() + &msg);