diff --git a/src/corelib/thread/qfutureinterface.h b/src/corelib/thread/qfutureinterface.h
index 9296c63f0b..8467047809 100644
--- a/src/corelib/thread/qfutureinterface.h
+++ b/src/corelib/thread/qfutureinterface.h
@@ -235,12 +235,12 @@ public:
 
     inline QFuture<T> future(); // implemented in qfuture.h
 
-    inline void reportResult(const T *result, int index = -1);
-    inline void reportAndMoveResult(T &&result, int index = -1);
-    inline void reportResult(T &&result, int index = -1);
-    inline void reportResult(const T &result, int index = -1);
-    inline void reportResults(const QList<T> &results, int beginIndex = -1, int count = -1);
-    inline void reportFinished(const T *result);
+    inline bool reportResult(const T *result, int index = -1);
+    inline bool reportAndMoveResult(T &&result, int index = -1);
+    inline bool reportResult(T &&result, int index = -1);
+    inline bool reportResult(const T &result, int index = -1);
+    inline bool reportResults(const QList<T> &results, int beginIndex = -1, int count = -1);
+    inline bool reportFinished(const T *result);
     void reportFinished()
     {
         QFutureInterfaceBase::reportFinished();
@@ -259,32 +259,32 @@ public:
 };
 
 template <typename T>
-inline void QFutureInterface<T>::reportResult(const T *result, int index)
+inline bool QFutureInterface<T>::reportResult(const T *result, int index)
 {
     std::lock_guard<QMutex> locker{mutex()};
-    if (this->queryState(Canceled) || this->queryState(Finished)) {
-        return;
-    }
+    if (this->queryState(Canceled) || this->queryState(Finished))
+        return false;
 
     QtPrivate::ResultStoreBase &store = resultStoreBase();
 
+    const int resultCountBefore = store.count();
+    const int insertIndex = store.addResult<T>(index, result);
+    if (insertIndex == -1)
+        return false;
     if (store.filterMode()) {
-        const int resultCountBefore = store.count();
-        if (store.addResult<T>(index, result) != -1)
-            this->reportResultsReady(resultCountBefore, store.count());
+        this->reportResultsReady(resultCountBefore, store.count());
     } else {
-        const int insertIndex = store.addResult<T>(index, result);
-        if (insertIndex != -1)
-            this->reportResultsReady(insertIndex, insertIndex + 1);
+        this->reportResultsReady(insertIndex, insertIndex + 1);
     }
+    return true;
 }
 
 template<typename T>
-void QFutureInterface<T>::reportAndMoveResult(T &&result, int index)
+bool QFutureInterface<T>::reportAndMoveResult(T &&result, int index)
 {
     std::lock_guard<QMutex> locker{mutex()};
     if (queryState(Canceled) || queryState(Finished))
-        return;
+        return false;
 
     QtPrivate::ResultStoreBase &store = resultStoreBase();
 
@@ -293,47 +293,50 @@ void QFutureInterface<T>::reportAndMoveResult(T &&result, int index)
     // Let's make sure it's not in pending results.
     if (insertIndex != -1 && (!store.filterMode() || oldResultCount < store.count()))
         reportResultsReady(insertIndex, store.count());
+    return insertIndex != -1;
 }
 
 template<typename T>
-void QFutureInterface<T>::reportResult(T &&result, int index)
+bool QFutureInterface<T>::reportResult(T &&result, int index)
 {
-    reportAndMoveResult(std::move(result), index);
+    return reportAndMoveResult(std::move(result), index);
 }
 
 template <typename T>
-inline void QFutureInterface<T>::reportResult(const T &result, int index)
+inline bool QFutureInterface<T>::reportResult(const T &result, int index)
 {
-    reportResult(&result, index);
+    return reportResult(&result, index);
 }
 
 template<typename T>
-inline void QFutureInterface<T>::reportResults(const QList<T> &_results, int beginIndex, int count)
+inline bool QFutureInterface<T>::reportResults(const QList<T> &_results, int beginIndex, int count)
 {
     std::lock_guard<QMutex> locker{mutex()};
-    if (this->queryState(Canceled) || this->queryState(Finished)) {
-        return;
-    }
+    if (this->queryState(Canceled) || this->queryState(Finished))
+        return false;
 
     auto &store = resultStoreBase();
 
+    const int resultCountBefore = store.count();
+    const int insertIndex = store.addResults(beginIndex, &_results, count);
+    if (insertIndex == -1)
+        return false;
     if (store.filterMode()) {
-        const int resultCountBefore = store.count();
-        if (store.addResults(beginIndex, &_results, count) != -1)
-            this->reportResultsReady(resultCountBefore, store.count());
+        this->reportResultsReady(resultCountBefore, store.count());
     } else {
-        const int insertIndex = store.addResults(beginIndex, &_results, count);
-        if (insertIndex != -1)
-            this->reportResultsReady(insertIndex, insertIndex + _results.count());
+        this->reportResultsReady(insertIndex, insertIndex + _results.count());
     }
+    return true;
 }
 
 template <typename T>
-inline void QFutureInterface<T>::reportFinished(const T *result)
+inline bool QFutureInterface<T>::reportFinished(const T *result)
 {
+    bool resultReported = false;
     if (result)
-        reportResult(result);
+        resultReported = reportResult(result);
     reportFinished();
+    return resultReported;
 }
 
 template <typename T>
@@ -427,9 +430,14 @@ public:
 
     inline QFuture<void> future(); // implemented in qfuture.h
 
-    void reportResult(const void *, int) { }
-    void reportResults(const QList<void> &, int) { }
-    void reportFinished(const void * = nullptr)
+    bool reportResult(const void *, int) { return false; }
+    bool reportResults(const QList<void> &, int) { return false; }
+    bool reportFinished(const void *)
+    {
+        reportFinished();
+        return false;
+    }
+    void reportFinished()
     {
         QFutureInterfaceBase::reportFinished();
         QFutureInterfaceBase::runContinuation();
diff --git a/src/corelib/thread/qpromise.h b/src/corelib/thread/qpromise.h
index 59c31de212..4225abd771 100644
--- a/src/corelib/thread/qpromise.h
+++ b/src/corelib/thread/qpromise.h
@@ -89,9 +89,9 @@ public:
     template<typename U = T,
              typename = QtPrivate::EnableForNonVoid<std::decay_t<U>>,
              typename = QtPrivate::EnableIfSameOrConvertible<std::decay_t<U>, std::decay_t<T>>>
-    void addResult(U &&result, int index = -1)
+    bool addResult(U &&result, int index = -1)
     {
-        d.reportResult(std::forward<U>(result), index);
+        return d.reportResult(std::forward<U>(result), index);
     }
 #ifndef QT_NO_EXCEPTIONS
     void setException(const QException &e) { d.reportException(e); }
@@ -118,8 +118,8 @@ public:
     }
 
 #if defined(Q_CLANG_QDOC)  // documentation-only simplified signatures
-    void addResult(const T &result, int index = -1) { }
-    void addResult(T &&result, int index = -1) { }
+    bool addResult(const T &result, int index = -1) { }
+    bool addResult(T &&result, int index = -1) { }
 #endif
 private:
     mutable QFutureInterface<T> d = QFutureInterface<T>();
diff --git a/src/corelib/thread/qpromise.qdoc b/src/corelib/thread/qpromise.qdoc
index 4b7b497b3f..279bc8766a 100644
--- a/src/corelib/thread/qpromise.qdoc
+++ b/src/corelib/thread/qpromise.qdoc
@@ -107,13 +107,17 @@
     Returns a future associated with this promise.
 */
 
-/*! \fn template <typename T> void QPromise<T>::addResult(const T &result, int index = -1)
+/*! \fn template <typename T> bool QPromise<T>::addResult(const T &result, int index = -1)
+    \fn template <typename T> bool QPromise<T>::addResult(T &&result, int index = -1)
 
     Adds \a result to the internal result collection at \a index position. If
     index is unspecified, \a result is added to the end of the collection.
 
-    \note addResult() rejects \a result if there's already another result in the
-    collection stored at the same index.
+    Returns \c true when \a result is added to the collection.
+
+    Returns \c false when this promise is in cancelled or finished state or when
+    \a result is rejected. addResult() rejects \a result if there's already
+    another result in the collection stored at the same index.
 
     You can get a result at a specific index by calling QFuture::resultAt().
 
@@ -124,11 +128,6 @@
     thinking if there are index gaps or not, use QFuture::results().
 */
 
-/*! \fn template <typename T> void QPromise<T>::addResult(T &&result, int index = -1)
-
-    \overload
-*/
-
 /*! \fn template<typename T> void QPromise<T>::setException(const QException &e)
 
     Sets exception \a e to be the result of the computation.
diff --git a/tests/auto/corelib/thread/qfuture/tst_qfuture.cpp b/tests/auto/corelib/thread/qfuture/tst_qfuture.cpp
index 99f2144528..2d78af8f94 100644
--- a/tests/auto/corelib/thread/qfuture/tst_qfuture.cpp
+++ b/tests/auto/corelib/thread/qfuture/tst_qfuture.cpp
@@ -653,7 +653,7 @@ void tst_QFuture::futureInterface()
         {
             QFutureInterface<int> i;
             i.reportStarted();
-            i.reportResult(10);
+            QVERIFY(i.reportResult(10));
             future = i.future();
             i.reportFinished();
         }
@@ -674,7 +674,7 @@ void tst_QFuture::futureInterface()
         QCOMPARE(intFuture.isStarted(), true);
         QCOMPARE(intFuture.isFinished(), false);
 
-        result.reportFinished(&value);
+        QVERIFY(result.reportFinished(&value));
 
         QCOMPARE(intFuture.isStarted(), true);
         QCOMPARE(intFuture.isFinished(), true);
@@ -701,9 +701,9 @@ void tst_QFuture::futureInterface()
 
     {
         QFutureInterface<int> i1;
-        i1.reportResult(1);
+        QVERIFY(i1.reportResult(1));
         QFutureInterface<int> i2;
-        i2.reportResult(2);
+        QVERIFY(i2.reportResult(2));
         swap(i1, i2);  // ADL must resolve this
         QCOMPARE(i1.resultReference(0), 2);
         QCOMPARE(i2.resultReference(0), 1);
@@ -867,15 +867,15 @@ void tst_QFuture::multipleResults()
     int result;
 
     result = 1;
-    a.reportResult(&result);
+    QVERIFY(a.reportResult(&result));
     QCOMPARE(f.resultAt(0), 1);
 
     result = 2;
-    a.reportResult(&result);
+    QVERIFY(a.reportResult(&result));
     QCOMPARE(f.resultAt(1), 2);
 
     result = 3;
-    a.reportResult(&result);
+    QVERIFY(a.reportResult(&result));
 
     result = 4;
     a.reportFinished(&result);
@@ -916,16 +916,16 @@ void tst_QFuture::indexedResults()
         QChar result;
 
         result = 'B';
-        Interface.reportResult(&result, 1);
+        QVERIFY(Interface.reportResult(&result, 1));
 
         QCOMPARE(f.resultAt(1), result);
 
         result = 'A';
-        Interface.reportResult(&result, 0);
+        QVERIFY(Interface.reportResult(&result, 0));
         QCOMPARE(f.resultAt(0), result);
 
         result = 'C';
-        Interface.reportResult(&result); // no index
+        QVERIFY(Interface.reportResult(&result)); // no index
         QCOMPARE(f.resultAt(2), result);
 
         Interface.reportFinished();
@@ -941,22 +941,22 @@ void tst_QFuture::indexedResults()
         int result;
 
         result = 0;
-        Interface.reportResult(&result, 0);
+        QVERIFY(Interface.reportResult(&result, 0));
         QVERIFY(f.isResultReadyAt(0));
         QCOMPARE(f.resultAt(0), 0);
 
         result = 3;
-        Interface.reportResult(&result, 3);
+        QVERIFY(Interface.reportResult(&result, 3));
         QVERIFY(f.isResultReadyAt(3));
         QCOMPARE(f.resultAt(3), 3);
 
         result = 2;
-        Interface.reportResult(&result, 2);
+        QVERIFY(Interface.reportResult(&result, 2));
         QVERIFY(f.isResultReadyAt(2));
         QCOMPARE(f.resultAt(2), 2);
 
         result = 4;
-        Interface.reportResult(&result); // no index
+        QVERIFY(Interface.reportResult(&result)); // no index
         QVERIFY(f.isResultReadyAt(4));
         QCOMPARE(f.resultAt(4), 4);
 
@@ -1013,7 +1013,7 @@ void tst_QFuture::resultsAfterFinished()
         QCOMPARE(f.resultCount(), 0);
 
         result = 1;
-        a.reportResult(&result);
+        QVERIFY(a.reportResult(&result));
         QCOMPARE(f.resultAt(0), 1);
 
         a.reportFinished();
@@ -1021,7 +1021,7 @@ void tst_QFuture::resultsAfterFinished()
         QCOMPARE(f.resultAt(0), 1);
         QCOMPARE(f.resultCount(), 1);
         result = 2;
-        a.reportResult(&result);
+        QVERIFY(!a.reportResult(&result));
         QCOMPARE(f.resultCount(), 1);
     }
     // cancel it
@@ -1034,7 +1034,7 @@ void tst_QFuture::resultsAfterFinished()
         QCOMPARE(f.resultCount(), 0);
 
         result = 1;
-        a.reportResult(&result);
+        QVERIFY(a.reportResult(&result));
         QCOMPARE(f.resultAt(0), 1);
         QCOMPARE(f.resultCount(), 1);
 
@@ -1044,7 +1044,7 @@ void tst_QFuture::resultsAfterFinished()
         QCOMPARE(f.resultCount(), 1);
 
         result = 2;
-        a.reportResult(&result);
+        QVERIFY(!a.reportResult(&result));
         a.reportFinished();
     }
 }
@@ -1057,9 +1057,9 @@ void tst_QFuture::resultsAsList()
 
     int result;
     result = 1;
-    a.reportResult(&result);
+    QVERIFY(a.reportResult(&result));
     result = 2;
-    a.reportResult(&result);
+    QVERIFY(a.reportResult(&result));
 
     a.reportFinished();
 
@@ -1500,7 +1500,7 @@ void tst_QFuture::voidConversions()
 
         QFuture<int> intFuture(&iface);
         int value = 10;
-        iface.reportFinished(&value);
+        QVERIFY(iface.reportFinished(&value));
 
         QFuture<void> voidFuture(intFuture);
         voidFuture = intFuture;
@@ -1515,7 +1515,7 @@ void tst_QFuture::voidConversions()
             iface.reportStarted();
 
             QFuture<QList<int> > listFuture(&iface);
-            iface.reportResult(QList<int>() << 1 << 2 << 3);
+            QVERIFY(iface.reportResult(QList<int>() << 1 << 2 << 3));
             voidFuture = listFuture;
         }
         QCOMPARE(voidFuture.resultCount(), 0);
@@ -2853,8 +2853,8 @@ void tst_QFuture::takeResults()
     const int expectedCount = 10;
 
     for (int i = 0; i < expectedCount; ++i) {
-        moveIface.reportAndMoveResult(UniquePtr{new int(0b101010)}, i);
-        copyIface.reportAndMoveResult(std::vector<int>{1,2,3,4,5}, i);
+        QVERIFY(moveIface.reportAndMoveResult(UniquePtr{new int(0b101010)}, i));
+        QVERIFY(copyIface.reportAndMoveResult(std::vector<int>{1,2,3,4,5}, i));
     }
 
     moveIface.reportFinished();
@@ -2872,7 +2872,7 @@ void tst_QFuture::takeResult()
 {
     QFutureInterface<UniquePtr> iface;
     iface.reportStarted();
-    iface.reportAndMoveResult(UniquePtr{new int(0b101010)}, 0);
+    QVERIFY(iface.reportAndMoveResult(UniquePtr{new int(0b101010)}, 0));
     iface.reportFinished();
 
     auto future = iface.future();
@@ -2956,9 +2956,9 @@ void tst_QFuture::resultsReadyAt()
     {
         int dummyResult = 0b101010;
         if (testMove)
-            iface.reportAndMoveResult(std::move(dummyResult), index);
+            QVERIFY(iface.reportAndMoveResult(std::move(dummyResult), index));
         else
-            iface.reportResult(&dummyResult, index);
+            QVERIFY(iface.reportResult(&dummyResult, index));
     };
 
     const QSignalSpy readyCounter(&watcher, &QFutureWatcher<int>::resultsReadyAt);
@@ -3144,9 +3144,9 @@ void tst_QFuture::rejectResultOverwrite()
 
     // init
     if (initResults.size() == 1)
-        iface.reportResult(initResults[0]);
+        QVERIFY(iface.reportResult(initResults[0]));
     else
-        iface.reportResults(initResults);
+        QVERIFY(iface.reportResults(initResults));
     QCOMPARE(f.resultCount(), initResults.size());
     QCOMPARE(f.resultAt(0), initResults[0]);
     QCOMPARE(f.results(), initResults);
@@ -3165,21 +3165,21 @@ void tst_QFuture::rejectResultOverwrite()
     {
         int result = -1;
         const auto originalCount = f.resultCount();
-        iface.reportResult(result, 0);
+        QVERIFY(!iface.reportResult(result, 0));
         QCOMPARE(f.resultCount(), originalCount);
         QCOMPARE(f.resultAt(0), initResults[0]);
     }
     // overwrite with rvalue
     {
         const auto originalCount = f.resultCount();
-        iface.reportResult(-1, 0);
+        QVERIFY(!iface.reportResult(-1, 0));
         QCOMPARE(f.resultCount(), originalCount);
         QCOMPARE(f.resultAt(0), initResults[0]);
     }
     // overwrite with array
     {
         const auto originalCount = f.resultCount();
-        iface.reportResults(QList<int> { -1, -2, -3 }, 0);
+        QVERIFY(!iface.reportResults(QList<int> { -1, -2, -3 }, 0));
         QCOMPARE(f.resultCount(), originalCount);
         QCOMPARE(f.resultAt(0), initResults[0]);
     }
@@ -3187,7 +3187,7 @@ void tst_QFuture::rejectResultOverwrite()
     // special case: add result by different index, overlapping with the vector
     if (initResults.size() > 1) {
         const auto originalCount = f.resultCount();
-        iface.reportResult(-1, 1);
+        QVERIFY(!iface.reportResult(-1, 1));
         QCOMPARE(f.resultCount(), originalCount);
         QCOMPARE(f.resultAt(1), initResults[1]);
     }
@@ -3221,9 +3221,9 @@ void tst_QFuture::rejectPendingResultOverwrite()
 
     // init
     if (initResults.size() == 1)
-        iface.reportResult(initResults[0], 1);
+        QVERIFY(iface.reportResult(initResults[0], 1));
     else
-        iface.reportResults(initResults, 1);
+        QVERIFY(iface.reportResults(initResults, 1));
     QCOMPARE(f.resultCount(), 0); // not visible yet
     if (!filterMode) {
         QCOMPARE(f.resultAt(1), initResults[0]);
@@ -3244,7 +3244,7 @@ void tst_QFuture::rejectPendingResultOverwrite()
     {
         int result = -1;
         const auto originalCount = f.resultCount();
-        iface.reportResult(result, 1);
+        QVERIFY(!iface.reportResult(result, 1));
         QCOMPARE(f.resultCount(), originalCount);
         if (!filterMode)
             QCOMPARE(f.resultAt(1), initResults[0]);
@@ -3252,7 +3252,7 @@ void tst_QFuture::rejectPendingResultOverwrite()
     // overwrite with rvalue
     {
         const auto originalCount = f.resultCount();
-        iface.reportResult(-1, 1);
+        QVERIFY(!iface.reportResult(-1, 1));
         QCOMPARE(f.resultCount(), originalCount);
         if (!filterMode)
             QCOMPARE(f.resultAt(1), initResults[0]);
@@ -3260,7 +3260,7 @@ void tst_QFuture::rejectPendingResultOverwrite()
     // overwrite with array
     {
         const auto originalCount = f.resultCount();
-        iface.reportResults(QList<int> { -1, -2 }, 1);
+        QVERIFY(!iface.reportResults(QList<int> { -1, -2 }, 1));
         QCOMPARE(f.resultCount(), originalCount);
         if (!filterMode)
             QCOMPARE(f.resultAt(1), initResults[0]);
@@ -3268,7 +3268,7 @@ void tst_QFuture::rejectPendingResultOverwrite()
     // special case: add result by different index, overlapping with the vector
     if (initResults.size() > 1) {
         const auto originalCount = f.resultCount();
-        iface.reportResult(-1, 2);
+        QVERIFY(!iface.reportResult(-1, 2));
         QCOMPARE(f.resultCount(), originalCount);
         if (!filterMode)
             QCOMPARE(f.resultAt(2), initResults[1]);
@@ -3284,7 +3284,7 @@ void tst_QFuture::rejectPendingResultOverwrite()
         f.resume();
     }
 
-    iface.reportResult(123, 0); // make results at 0 and 1 accessible
+    QVERIFY(iface.reportResult(123, 0)); // make results at 0 and 1 accessible
     QCOMPARE(f.resultCount(), initResults.size() + 1);
     QCOMPARE(f.resultAt(1), initResults[0]);
     initResults.prepend(123);
diff --git a/tests/auto/corelib/thread/qpromise/tst_qpromise.cpp b/tests/auto/corelib/thread/qpromise/tst_qpromise.cpp
index 62e3711d42..600c0fd150 100644
--- a/tests/auto/corelib/thread/qpromise/tst_qpromise.cpp
+++ b/tests/auto/corelib/thread/qpromise/tst_qpromise.cpp
@@ -171,7 +171,7 @@ void tst_QPromise::addResult()
     // add as lvalue
     int resultAt0 = 456;
     {
-        promise.addResult(resultAt0);
+        QVERIFY(promise.addResult(resultAt0));
         QCOMPARE(f.resultCount(), 1);
         QCOMPARE(f.result(), resultAt0);
         QCOMPARE(f.resultAt(0), resultAt0);
@@ -179,14 +179,14 @@ void tst_QPromise::addResult()
     // add as rvalue
     {
         int result = 789;
-        promise.addResult(789);
+        QVERIFY(promise.addResult(789));
         QCOMPARE(f.resultCount(), 2);
         QCOMPARE(f.resultAt(1), result);
     }
     // add at position
     {
         int result = 56238;
-        promise.addResult(result, 2);
+        QVERIFY(promise.addResult(result, 2));
         QCOMPARE(f.resultCount(), 3);
         QCOMPARE(f.resultAt(2), result);
     }
@@ -194,14 +194,14 @@ void tst_QPromise::addResult()
     {
         int result = -1;
         const auto originalCount = f.resultCount();
-        promise.addResult(result, 0);
+        QVERIFY(!promise.addResult(result, 0));
         QCOMPARE(f.resultCount(), originalCount);
         QCOMPARE(f.resultAt(0), resultAt0); // overwrite does not work
     }
     // add as rvalue at position and overwrite
     {
         const auto originalCount = f.resultCount();
-        promise.addResult(-1, 0);
+        QVERIFY(!promise.addResult(-1, 0));
         QCOMPARE(f.resultCount(), originalCount);
         QCOMPARE(f.resultAt(0), resultAt0); // overwrite does not work
     }
@@ -223,9 +223,9 @@ void tst_QPromise::addResultOutOfOrder()
     {
         QPromise<int> promise;
         auto f = promise.future();
-        promise.addResult(456, 1);
+        QVERIFY(promise.addResult(456, 1));
         QCOMPARE(f.resultCount(), 0);
-        promise.addResult(123, 0);
+        QVERIFY(promise.addResult(123, 0));
 
         QList<int> expected({123, 456});
         RUN_TEST_FUNC(compareResults, f, expected);
@@ -236,16 +236,16 @@ void tst_QPromise::addResultOutOfOrder()
     {
         QPromise<int> promise;
         auto f = promise.future();
-        promise.addResult(0, 0);
-        promise.addResult(1, 1);
-        promise.addResult(3, 3);  // intentional gap here
+        QVERIFY(promise.addResult(0, 0));
+        QVERIFY(promise.addResult(1, 1));
+        QVERIFY(promise.addResult(3, 3));  // intentional gap here
 
         QList<int> expectedWhenGapExists({0, 1});
         RUN_TEST_FUNC(compareResults, f, expectedWhenGapExists);
         QCOMPARE(f.resultAt(3), 3);
 
         QList<int> expectedWhenNoGap({0, 1, 2, 3});
-        promise.addResult(2, 2);  // fill a gap with a value
+        QVERIFY(promise.addResult(2, 2));  // fill a gap with a value
         RUN_TEST_FUNC(compareResults, f, expectedWhenNoGap);
         QCOMPARE(f.results(), expectedWhenNoGap);
     }