diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index 5baa69270e5..d52722afb73 100644
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -970,6 +970,15 @@
 #define Q_DECL_ENUMERATOR_DEPRECATED Q_DECL_DEPRECATED
 #define Q_DECL_ENUMERATOR_DEPRECATED_X(x) Q_DECL_DEPRECATED_X(x)
 
+// [[nodiscard]] constructor
+#ifndef Q_NODISCARD_CTOR
+#  if __has_cpp_attribute(nodiscard) >= 201907L
+#    define Q_NODISCARD_CTOR [[nodiscard]]
+#  else
+#    define Q_NODISCARD_CTOR
+#  endif
+#endif
+
 /*
  * Fallback macros to certain compiler features
  */
diff --git a/src/corelib/thread/qmutex.h b/src/corelib/thread/qmutex.h
index af77f556fd4..407473c799f 100644
--- a/src/corelib/thread/qmutex.h
+++ b/src/corelib/thread/qmutex.h
@@ -231,6 +231,7 @@ template <typename Mutex>
 class [[nodiscard]] QMutexLocker
 {
 public:
+    Q_NODISCARD_CTOR
     inline explicit QMutexLocker(Mutex *mutex) QT_MUTEX_LOCK_NOEXCEPT
     {
         m_mutex = mutex;
@@ -240,6 +241,7 @@ public:
         }
     }
 
+    Q_NODISCARD_CTOR
     inline QMutexLocker(QMutexLocker &&other) noexcept
         : m_mutex(std::exchange(other.m_mutex, nullptr)),
           m_isLocked(std::exchange(other.m_isLocked, false))
@@ -326,6 +328,7 @@ template <typename Mutex>
 class [[nodiscard]] QMutexLocker
 {
 public:
+    Q_NODISCARD_CTOR
     inline explicit QMutexLocker(Mutex *) noexcept {}
     inline ~QMutexLocker() noexcept {}
 
diff --git a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
index 3f4e903a9a5..3d9759ff5bf 100644
--- a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
+++ b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
@@ -37,6 +37,7 @@ private slots:
     void qRoundDoubles();
     void PRImacros();
     void testqToUnderlying();
+    void nodiscardConstructor();
 };
 
 extern "C" {        // functions in qglobal.c
@@ -691,5 +692,25 @@ void tst_QGlobal::testqToUnderlying()
     QCOMPARE(qToUnderlying(EE2), 456UL);
 }
 
+void tst_QGlobal::nodiscardConstructor()
+{
+    // Syntax-only test, just to make sure that Q_NODISCARD_CTOR compiles
+    // on all platforms.
+    // Other code is just to silence all various compiler warnings about
+    // unused private members or methods.
+    class Test {
+    public:
+        Q_NODISCARD_CTOR explicit Test(int val) : m_val(val) {}
+
+        int get() const { return m_val; }
+
+    private:
+        int m_val;
+    };
+
+    Test t{42};
+    QCOMPARE(t.get(), 42);
+}
+
 QTEST_APPLESS_MAIN(tst_QGlobal)
 #include "tst_qglobal.moc"