diff --git a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
index 16136b67a34..2d877fbe5ac 100644
--- a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
+++ b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
@@ -893,6 +893,8 @@ void tst_QWidget::fontPropagation()
     QVERIFY(four->testAttribute(Qt::WA_SetFont));
 }
 
+// QPropagationTestWidget is not found in QApplicationPrivate::widgetPalettes
+// and therefore falls back to the system palette
 class QPropagationTestWidget : public QWidget
 {
     Q_OBJECT