diff --git a/dll/win32/comctl32/treeview.c b/dll/win32/comctl32/treeview.c
index 9e5eb43894f..e4a30d38103 100644
--- a/dll/win32/comctl32/treeview.c
+++ b/dll/win32/comctl32/treeview.c
@@ -5825,7 +5825,9 @@ TREEVIEW_WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 	return TREEVIEW_HScroll(infoPtr, wParam);
 
     case WM_KEYDOWN:
+#ifndef __REACTOS__
     case WM_SYSKEYDOWN:
+#endif
 	return TREEVIEW_KeyDown(infoPtr, wParam);
 
     case WM_KILLFOCUS: