diff --git a/Telegram/SourceFiles/platform/win/main_window_win.cpp b/Telegram/SourceFiles/platform/win/main_window_win.cpp
index 8c05a1df2c..10d6253638 100644
--- a/Telegram/SourceFiles/platform/win/main_window_win.cpp
+++ b/Telegram/SourceFiles/platform/win/main_window_win.cpp
@@ -252,7 +252,7 @@ void MainWindow::workmodeUpdated(DBIWorkMode mode) {
 		psSetupTrayIcon();
 		HWND psOwner = (HWND)GetWindowLongPtr(ps_hWnd, GWLP_HWNDPARENT);
 		if (!psOwner) {
-			SetWindowLongPtr(ps_hWnd, GWLP_HWNDPARENT, (LONG)ps_tbHider_hWnd);
+			SetWindowLongPtr(ps_hWnd, GWLP_HWNDPARENT, (LONG_PTR)ps_tbHider_hWnd);
 		}
 	} break;