diff --git a/tests/manual/windowflags/previewwindow.cpp b/tests/manual/windowflags/previewwindow.cpp
index 0771e54cd13..7534bdf9c20 100644
--- a/tests/manual/windowflags/previewwindow.cpp
+++ b/tests/manual/windowflags/previewwindow.cpp
@@ -21,7 +21,7 @@ PreviewWindow::PreviewWindow(QWindow *parent)
     resize(400, 400);
 }
 
-void PreviewWindow::paintEvent(QPaintEvent *event)
+void PreviewWindow::paintEvent(QPaintEvent *)
 {
     QPainter painter(this);
     QRect rect(0, 0, width(), height());