diff --git a/src/corelib/serialization/qjsoncbor.cpp b/src/corelib/serialization/qjsoncbor.cpp
index 53c2a16ddbe..a2aec8066ed 100644
--- a/src/corelib/serialization/qjsoncbor.cpp
+++ b/src/corelib/serialization/qjsoncbor.cpp
@@ -718,12 +718,15 @@ QCborValue QCborValue::fromVariant(const QVariant &variant)
     case QMetaType::UShort:
     case QMetaType::Int:
     case QMetaType::LongLong:
+    case QMetaType::Long:
     case QMetaType::UInt:
         return variant.toLongLong();
+    case QMetaType::ULong:
     case QMetaType::ULongLong:
         if (variant.toULongLong() <= static_cast<uint64_t>(std::numeric_limits<qint64>::max()))
             return variant.toLongLong();
         Q_FALLTHROUGH();
+    case QMetaType::Float16:
     case QMetaType::Float:
     case QMetaType::Double:
         return variant.toDouble();
diff --git a/src/corelib/serialization/qjsonvalue.cpp b/src/corelib/serialization/qjsonvalue.cpp
index 52be7712fdc..63f2f438965 100644
--- a/src/corelib/serialization/qjsonvalue.cpp
+++ b/src/corelib/serialization/qjsonvalue.cpp
@@ -484,12 +484,15 @@ QJsonValue QJsonValue::fromVariant(const QVariant &variant)
     case QMetaType::UShort:
     case QMetaType::Int:
     case QMetaType::UInt:
+    case QMetaType::Long:
     case QMetaType::LongLong:
         return QJsonValue(variant.toLongLong());
+    case QMetaType::ULong:
     case QMetaType::ULongLong:
         if (variant.toULongLong() <= static_cast<uint64_t>(std::numeric_limits<qint64>::max()))
             return QJsonValue(variant.toLongLong());
         Q_FALLTHROUGH();
+    case QMetaType::Float16:
     case QMetaType::Float:
     case QMetaType::Double: {
         double v = variant.toDouble();
diff --git a/tests/auto/corelib/serialization/json/tst_qtjson.cpp b/tests/auto/corelib/serialization/json/tst_qtjson.cpp
index 64e77f1bcd0..4d970c52f9a 100644
--- a/tests/auto/corelib/serialization/json/tst_qtjson.cpp
+++ b/tests/auto/corelib/serialization/json/tst_qtjson.cpp
@@ -1654,8 +1654,11 @@ void tst_QtJson::fromVariant_data()
     bool boolValue = true;
     int intValue = -1;
     uint uintValue = 1;
+    long longValue = -2;
+    ulong ulongValue = 2;
     qlonglong longlongValue = -2;
     qulonglong ulonglongValue = 2;
+    qfloat16 float16Value{2.25f};
     float floatValue = 3.3f;
     double doubleValue = 4.4;
     QString stringValue("str");
@@ -1686,21 +1689,27 @@ void tst_QtJson::fromVariant_data()
 
     QVariantMap variantMap;
     variantMap["bool"] = boolValue;
+    variantMap["float16"] = QVariant::fromValue(float16Value);
     variantMap["float"] = floatValue;
+    variantMap["double"] = doubleValue;
     variantMap["string"] = stringValue;
     variantMap["array"] = variantList;
     variantMap["null"] = QVariant::fromValue(nullptr);
     variantMap["default"] = QVariant();
     QVariantHash variantHash;
     variantHash["bool"] = boolValue;
+    variantHash["float16"] = QVariant::fromValue(float16Value);
     variantHash["float"] = floatValue;
+    variantHash["double"] = doubleValue;
     variantHash["string"] = stringValue;
     variantHash["array"] = variantList;
     variantHash["null"] = QVariant::fromValue(nullptr);
     variantHash["default"] = QVariant();
     QJsonObject jsonObject;
     jsonObject["bool"] = boolValue;
+    jsonObject["float16"] = float(float16Value);
     jsonObject["float"] = floatValue;
+    jsonObject["double"] = doubleValue;
     jsonObject["string"] = stringValue;
     jsonObject["array"] = jsonArray_variant;
     jsonObject["null"] = QJsonValue::Null;
@@ -1711,8 +1720,11 @@ void tst_QtJson::fromVariant_data()
     QTest::newRow("bool") << QVariant(boolValue) <<  QJsonValue(boolValue);
     QTest::newRow("int") << QVariant(intValue) <<  QJsonValue(intValue);
     QTest::newRow("uint") << QVariant(uintValue) <<  QJsonValue(static_cast<qint64>(uintValue));
+    QTest::newRow("long") << QVariant::fromValue(longValue) <<  QJsonValue(static_cast<qint64>(longValue));
+    QTest::newRow("ulong") << QVariant::fromValue(ulongValue) <<  QJsonValue(static_cast<qint64>(ulongValue));
     QTest::newRow("longlong") << QVariant(longlongValue) <<  QJsonValue(longlongValue);
     QTest::newRow("ulonglong") << QVariant(ulonglongValue) <<  QJsonValue(static_cast<double>(ulonglongValue));
+    QTest::newRow("float16") << QVariant::fromValue(float16Value) <<  QJsonValue(float(float16Value));
     QTest::newRow("float") << QVariant(floatValue) <<  QJsonValue(floatValue);
     QTest::newRow("double") << QVariant(doubleValue) <<  QJsonValue(doubleValue);
     QTest::newRow("string") << QVariant(stringValue) <<  QJsonValue(stringValue);
diff --git a/tests/auto/corelib/serialization/qcborvalue_json/tst_qcborvalue_json.cpp b/tests/auto/corelib/serialization/qcborvalue_json/tst_qcborvalue_json.cpp
index 941bfa40083..f12a57cca82 100644
--- a/tests/auto/corelib/serialization/qcborvalue_json/tst_qcborvalue_json.cpp
+++ b/tests/auto/corelib/serialization/qcborvalue_json/tst_qcborvalue_json.cpp
@@ -24,7 +24,7 @@ private slots:
     void taggedByteArrayToJson_data();
     void taggedByteArrayToJson();
 
-    void fromVariant_data() { toVariant_data(); }
+    void fromVariant_data();
     void fromVariant();
     void fromJson_data();
     void fromJson();
@@ -182,6 +182,31 @@ void tst_QCborValue_Json::taggedByteArrayToJson()
     QCOMPARE(QCborArray({v}).toJsonArray(), QJsonArray({json}));
 }
 
+void tst_QCborValue_Json::fromVariant_data()
+{
+    toVariant_data();
+
+    auto addIntegral = [](auto number) {
+        QCborValue cv = qint64(number);
+        QJsonValue jv = qint64(number);
+        QVariant vv = QVariant::fromValue(number);
+        QTest::addRow("%s:%lld", vv.typeName(), qlonglong(number)) << cv << vv << jv;
+    };
+
+    // exercise different QVariant numeric types
+    addIntegral(short(-1));
+    addIntegral(ushort(1));
+    // int already tested
+    addIntegral(65536U);
+    addIntegral(-0x7fff'ffffL);
+    addIntegral(0xffff'ffffUL);
+    addIntegral(-0x1'0000'0000LL);
+    addIntegral(0x1000'0000'0000ULL);
+
+    QTest::addRow("float:1.875") << QCborValue(1.875) << QVariant::fromValue(1.875f) << QJsonValue(1.875);
+    QTest::addRow("qfloat16:-0.5") << QCborValue(-0.5) << QVariant::fromValue(qfloat16(-0.5f)) << QJsonValue(-0.5);
+}
+
 void tst_QCborValue_Json::fromVariant()
 {
     QFETCH(QCborValue, v);