diff --git a/cockatrice/src/client/ui/window_main.cpp b/cockatrice/src/client/ui/window_main.cpp
index 89a686f61..7dabc96c6 100644
--- a/cockatrice/src/client/ui/window_main.cpp
+++ b/cockatrice/src/client/ui/window_main.cpp
@@ -574,6 +574,9 @@ void MainWindow::registerError(Response::ResponseCode r, QString reasonStr, quin
         case Response::RespRegistrationFailed:
             QMessageBox::critical(this, tr("Error"), tr("Registration failed for a technical problem on the server."));
             break;
+        case Response::RespNotConnected:
+            QMessageBox::critical(this, tr("Error"), tr("The connection to the server has been lost."));
+            break;
         default:
             QMessageBox::critical(this, tr("Error"),
                                   tr("Unknown registration error: %1").arg(static_cast<int>(r)) +
diff --git a/cockatrice/src/server/remote/remote_client.cpp b/cockatrice/src/server/remote/remote_client.cpp
index 5812483ad..72391b746 100644
--- a/cockatrice/src/server/remote/remote_client.cpp
+++ b/cockatrice/src/server/remote/remote_client.cpp
@@ -339,6 +339,11 @@ void RemoteClient::registerResponse(const Response &response)
             emit registerAcceptedNeedsActivate();
             doLogin();
             break;
+        case Response::RespNotConnected:
+            // this response is created by the client from doDisconnectFromServer, do not call it again!
+            emit registerError(response.response_code(), QString::fromStdString(resp.denied_reason_str()),
+                               static_cast<quint32>(resp.denied_end_time()));
+            break;
         default:
             emit registerError(response.response_code(), QString::fromStdString(resp.denied_reason_str()),
                                static_cast<quint32>(resp.denied_end_time()));