diff --git a/tests/auto/corelib/io/qdebug/tst_qdebug.cpp b/tests/auto/corelib/io/qdebug/tst_qdebug.cpp
index 7592a12a490..e0f677e1511 100644
--- a/tests/auto/corelib/io/qdebug/tst_qdebug.cpp
+++ b/tests/auto/corelib/io/qdebug/tst_qdebug.cpp
@@ -875,7 +875,7 @@ void tst_QDebug::qDebugStdUnorderedMap() const
 void tst_QDebug::qDebugStdUnorderedSet() const
 {
     QByteArray file, function;
-    int line = 0;
+    [[maybe_unused]] int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
 
     {
diff --git a/tests/auto/corelib/time/qtimezone/tst_qtimezone.cpp b/tests/auto/corelib/time/qtimezone/tst_qtimezone.cpp
index d834bedb2e7..cc3e5b9b0d5 100644
--- a/tests/auto/corelib/time/qtimezone/tst_qtimezone.cpp
+++ b/tests/auto/corelib/time/qtimezone/tst_qtimezone.cpp
@@ -2135,7 +2135,7 @@ void tst_QTimeZone::stdCompatibility_data()
     qDebug() << "Using tzdb version:" << QByteArrayView(tzdb.version);
 
     for (const std::chrono::time_zone &zone : tzdb.zones)
-        QTest::addRow(zone.name().data()) << &zone;
+        QTest::addRow("%s", zone.name().data()) << &zone;
 #else
     QSKIP("This test requires C++20's <chrono>.");
 #endif
diff --git a/tests/manual/network_stresstest/minihttpserver.h b/tests/manual/network_stresstest/minihttpserver.h
index d630e29c9a4..1b6cb79c4c4 100644
--- a/tests/manual/network_stresstest/minihttpserver.h
+++ b/tests/manual/network_stresstest/minihttpserver.h
@@ -24,7 +24,7 @@ public:
     int port() { return portnum; }
 
 protected:
-    void run();
+    void run() override;
 
 private slots:
     void handleConnection();
diff --git a/tests/manual/rhi/rhiwidgetproto/rhiwidget.cpp b/tests/manual/rhi/rhiwidgetproto/rhiwidget.cpp
index d535c655d0b..a04cc7347da 100644
--- a/tests/manual/rhi/rhiwidgetproto/rhiwidget.cpp
+++ b/tests/manual/rhi/rhiwidgetproto/rhiwidget.cpp
@@ -154,7 +154,6 @@ QPlatformBackingStoreRhiConfig QRhiWidgetPrivate::rhiConfig() const
 
 void QRhiWidgetPrivate::ensureRhi()
 {
-    Q_Q(QRhiWidget);
     QRhi *currentRhi = QWidgetPrivate::rhi();
     if (currentRhi && currentRhi->backend() != QBackingStoreRhiSupport::apiToRhiBackend(config.api())) {
         qWarning("The top-level window is already using another graphics API for composition, "