diff --git a/src/widgets/kernel/qrhiwidget.h b/src/widgets/kernel/qrhiwidget.h
index 09fc2b94538..68f0ae46ad4 100644
--- a/src/widgets/kernel/qrhiwidget.h
+++ b/src/widgets/kernel/qrhiwidget.h
@@ -69,7 +69,7 @@ public:
     QImage grabFramebuffer() const;
 
 protected:
-    QRhiWidget(QRhiWidgetPrivate &dd, QWidget *parent = nullptr, Qt::WindowFlags f = {});
+    explicit QRhiWidget(QRhiWidgetPrivate &dd, QWidget *parent = nullptr, Qt::WindowFlags f = {});
 
     bool isAutoRenderTargetEnabled() const;
     void setAutoRenderTarget(bool enabled);