diff --git a/Telegram/SourceFiles/window/window_title_qt.cpp b/Telegram/SourceFiles/window/window_title_qt.cpp
index 2dbc133b6..2ee27b67f 100644
--- a/Telegram/SourceFiles/window/window_title_qt.cpp
+++ b/Telegram/SourceFiles/window/window_title_qt.cpp
@@ -306,6 +306,12 @@ void TitleWidgetQt::windowStateChanged(Qt::WindowState state) {
 void TitleWidgetQt::visibleChanged(bool visible) {
 	if (visible) {
 		updateWindowExtents();
+
+		// workaround a bug in Qt 5.12, works ok in Qt 5.15
+		// https://github.com/telegramdesktop/tdesktop/issues/10119
+		if (!_windowWasFrameless) {
+			toggleFramelessWindow(true);
+		}
 	}
 }