diff --git a/src/corelib/tools/qsize.cpp b/src/corelib/tools/qsize.cpp
index d5e8e4c71b..0165a4095c 100644
--- a/src/corelib/tools/qsize.cpp
+++ b/src/corelib/tools/qsize.cpp
@@ -266,15 +266,15 @@ QSize QSize::scaled(const QSize &s, Qt::AspectRatioMode mode) const noexcept
 */
 
 /*!
-    \fn bool QSize::operator==(const QSize &s1, const QSize &s2)
+    \fn bool QSize::operator==(const QSize &lhs, const QSize &rhs)
 
-    Returns \c true if \a s1 and \a s2 are equal; otherwise returns \c false.
+    Returns \c true if \a lhs and \a rhs are equal; otherwise returns \c false.
 */
 
 /*!
-    \fn bool QSize::operator!=(const QSize &s1, const QSize &s2)
+    \fn bool QSize::operator!=(const QSize &lhs, const QSize &rhs)
 
-    Returns \c true if \a s1 and \a s2 are different; otherwise returns \c false.
+    Returns \c true if \a lhs and \a rhs are different; otherwise returns \c false.
 */
 
 /*!
@@ -714,9 +714,9 @@ QSizeF QSizeF::scaled(const QSizeF &s, Qt::AspectRatioMode mode) const noexcept
 */
 
 /*!
-    \fn bool QSizeF::operator==(const QSizeF &s1, const QSizeF &s2)
+    \fn bool QSizeF::operator==(const QSizeF &lhs, const QSizeF &rhs)
 
-    Returns \c true if \a s1 and \a s2 are approximately equal; otherwise
+    Returns \c true if \a lhs and \a rhs are approximately equal; otherwise
     returns false.
 
     \warning This function does not check for strict equality; instead,
@@ -726,9 +726,9 @@ QSizeF QSizeF::scaled(const QSizeF &s, Qt::AspectRatioMode mode) const noexcept
 */
 
 /*!
-    \fn bool QSizeF::operator!=(const QSizeF &s1, const QSizeF &s2)
+    \fn bool QSizeF::operator!=(const QSizeF &lhs, const QSizeF &rhs)
 
-    Returns \c true if \a s1 and \a s2 are sufficiently different; otherwise
+    Returns \c true if \a lhs and \a rhs are sufficiently different; otherwise
     returns \c false.
 
     \warning This function does not check for strict inequality; instead,
diff --git a/src/corelib/tools/qsize.h b/src/corelib/tools/qsize.h
index a5eaf34afe..604f110ebe 100644
--- a/src/corelib/tools/qsize.h
+++ b/src/corelib/tools/qsize.h
@@ -59,10 +59,10 @@ public:
     constexpr inline QSize &operator*=(qreal c) noexcept;
     inline QSize &operator/=(qreal c);
 
-    friend inline constexpr bool operator==(const QSize &s1, const QSize &s2) noexcept
+private:
+    friend constexpr bool comparesEqual(const QSize &s1, const QSize &s2) noexcept
     { return s1.wd == s2.wd && s1.ht == s2.ht; }
-    friend inline constexpr bool operator!=(const QSize &s1, const QSize &s2) noexcept
-    { return s1.wd != s2.wd || s1.ht != s2.ht; }
+    Q_DECLARE_EQUALITY_COMPARABLE_LITERAL_TYPE(QSize)
     friend inline constexpr QSize operator+(const QSize &s1, const QSize &s2) noexcept
     { return QSize(s1.wd + s2.wd, s1.ht + s2.ht); }
     friend inline constexpr QSize operator-(const QSize &s1, const QSize &s2) noexcept
@@ -75,6 +75,7 @@ public:
     { Q_ASSERT(!qFuzzyIsNull(c)); return QSize(qRound(s.wd / c), qRound(s.ht / c)); }
     friend inline constexpr size_t qHash(const QSize &, size_t) noexcept;
 
+public:
 #if defined(Q_OS_DARWIN) || defined(Q_QDOC)
     [[nodiscard]] CGSize toCGSize() const noexcept;
 #endif
@@ -242,16 +243,19 @@ public:
     constexpr inline QSizeF &operator*=(qreal c) noexcept;
     inline QSizeF &operator/=(qreal c);
 
+private:
     QT_WARNING_PUSH
     QT_WARNING_DISABLE_FLOAT_COMPARE
-    friend constexpr inline bool operator==(const QSizeF &s1, const QSizeF &s2)
+    friend constexpr bool comparesEqual(const QSizeF &s1, const QSizeF &s2) noexcept
     {
         return ((!s1.wd || !s2.wd) ? qFuzzyIsNull(s1.wd - s2.wd) : qFuzzyCompare(s1.wd, s2.wd))
             && ((!s1.ht || !s2.ht) ? qFuzzyIsNull(s1.ht - s2.ht) : qFuzzyCompare(s1.ht, s2.ht));
     }
     QT_WARNING_POP
-    friend constexpr inline bool operator!=(const QSizeF &s1, const QSizeF &s2)
-    { return !(s1 == s2); }
+    Q_DECLARE_EQUALITY_COMPARABLE_LITERAL_TYPE(QSizeF)
+    friend constexpr bool comparesEqual(const QSizeF &lhs, const QSize &rhs) noexcept
+    { return comparesEqual(lhs, rhs.toSizeF()); }
+    Q_DECLARE_EQUALITY_COMPARABLE_LITERAL_TYPE(QSizeF, QSize)
     friend constexpr inline QSizeF operator+(const QSizeF &s1, const QSizeF &s2) noexcept
     { return QSizeF(s1.wd + s2.wd, s1.ht + s2.ht); }
     friend constexpr inline QSizeF operator-(const QSizeF &s1, const QSizeF &s2) noexcept
@@ -263,6 +267,7 @@ public:
     friend inline QSizeF operator/(const QSizeF &s, qreal c)
     { Q_ASSERT(!qFuzzyIsNull(c)); return QSizeF(s.wd / c, s.ht / c); }
 
+public:
     constexpr inline QSize toSize() const noexcept;
 
 #if defined(Q_OS_DARWIN) || defined(Q_QDOC)
diff --git a/tests/auto/corelib/tools/qsize/CMakeLists.txt b/tests/auto/corelib/tools/qsize/CMakeLists.txt
index 91de696ddd..4a4c96b52c 100644
--- a/tests/auto/corelib/tools/qsize/CMakeLists.txt
+++ b/tests/auto/corelib/tools/qsize/CMakeLists.txt
@@ -14,4 +14,6 @@ endif()
 qt_internal_add_test(tst_qsize
     SOURCES
         tst_qsize.cpp
+    LIBRARIES
+        Qt::TestPrivate
 )
diff --git a/tests/auto/corelib/tools/qsize/tst_qsize.cpp b/tests/auto/corelib/tools/qsize/tst_qsize.cpp
index c9699c5e76..d379275dd8 100644
--- a/tests/auto/corelib/tools/qsize/tst_qsize.cpp
+++ b/tests/auto/corelib/tools/qsize/tst_qsize.cpp
@@ -24,6 +24,7 @@ CHECK(const &&);
 #undef CHECK
 
 #include <QTest>
+#include <QtTest/private/qcomparisontesthelper_p.h>
 #include <qsize.h>
 
 #include <array>
@@ -34,6 +35,10 @@ class tst_QSize : public QObject
 {
     Q_OBJECT
 private slots:
+    void compareCompiles();
+    void compare_data();
+    void compare();
+
     void getSetCheck();
     void scale();
 
@@ -55,6 +60,38 @@ private slots:
     void structuredBinding();
 };
 
+void tst_QSize::compareCompiles()
+{
+    QTestPrivate::testEqualityOperatorsCompile<QSize>();
+}
+
+void tst_QSize::compare_data()
+{
+    QTest::addColumn<QSize>("lhs");
+    QTest::addColumn<QSize>("rhs");
+    QTest::addColumn<bool>("result");
+
+    auto row = [](QSize lhs, QSize rhs, bool res) {
+        QTest::addRow("(%d, %d) vs (%d, %d)", lhs.width(), lhs.height(), rhs.width(), rhs.height())
+                << lhs << rhs << res;
+    };
+
+    row(QSize(0, 0), QSize(0, 0), true);
+    row(QSize(1, 0), QSize(0, 1), false);
+    row(QSize(-1, -1), QSize(-1, -1), true);
+    row(QSize(-1, -1), QSize(1, 1), false);
+    row(QSize(INT_MIN, INT_MAX), QSize(INT_MAX, INT_MIN), false);
+}
+
+void tst_QSize::compare()
+{
+    QFETCH(QSize, lhs);
+    QFETCH(QSize, rhs);
+    QFETCH(bool, result);
+
+    QT_TEST_EQUALITY_OPS(lhs, rhs, result);
+}
+
 // Testing get/set functions
 void tst_QSize::getSetCheck()
 {
diff --git a/tests/auto/corelib/tools/qsizef/CMakeLists.txt b/tests/auto/corelib/tools/qsizef/CMakeLists.txt
index 9adaafe2ea..d8a1c7f46e 100644
--- a/tests/auto/corelib/tools/qsizef/CMakeLists.txt
+++ b/tests/auto/corelib/tools/qsizef/CMakeLists.txt
@@ -14,4 +14,6 @@ endif()
 qt_internal_add_test(tst_qsizef
     SOURCES
         tst_qsizef.cpp
+    LIBRARIES
+        Qt::TestPrivate
 )
diff --git a/tests/auto/corelib/tools/qsizef/tst_qsizef.cpp b/tests/auto/corelib/tools/qsizef/tst_qsizef.cpp
index ee33fa13b6..12e30dfa57 100644
--- a/tests/auto/corelib/tools/qsizef/tst_qsizef.cpp
+++ b/tests/auto/corelib/tools/qsizef/tst_qsizef.cpp
@@ -24,14 +24,21 @@ CHECK(const &&);
 #undef CHECK
 
 #include <QTest>
+#include <QtTest/private/qcomparisontesthelper_p.h>
 #include <qsize.h>
 
 Q_DECLARE_METATYPE(QMarginsF)
 
+static constexpr qreal qreal_min = std::numeric_limits<qreal>::min();
+
 class tst_QSizeF : public QObject
 {
     Q_OBJECT
 private slots:
+    void compareCompiles();
+    void compare_data();
+    void compare();
+
     void isNull_data();
     void isNull();
 
@@ -52,6 +59,47 @@ private slots:
     void structuredBinding();
 };
 
+void tst_QSizeF::compareCompiles()
+{
+    QTestPrivate::testEqualityOperatorsCompile<QSizeF>();
+    QTestPrivate::testEqualityOperatorsCompile<QSizeF, QSize>();
+}
+
+void tst_QSizeF::compare_data()
+{
+    QTest::addColumn<QSizeF>("lhs");
+    QTest::addColumn<QSizeF>("rhs");
+    QTest::addColumn<bool>("result");
+    QTest::addColumn<bool>("mixedResult");
+
+    auto row = [&](QSizeF lhs, QSizeF rhs, bool res, bool mixedRes) {
+        QString str;
+        QDebug dbg(&str);
+        dbg.nospace() << "(" << lhs.width() << ", " << lhs.height() << ") vs "
+                      << "(" << rhs.width() << ", " << rhs.height() << ")";
+        QTest::addRow("%s", str.toLatin1().constData()) << lhs << rhs << res << mixedRes;
+    };
+
+    row(QSizeF(0.0, 0.0), QSizeF(0.0, 0.0), true, true);
+    row(QSizeF(1.0, 2.0), QSizeF(1.0, 2.0), true, true);
+    row(QSizeF(1.0, -1.0), QSizeF(-1.0, 1.0), false, false);
+    row(QSizeF(0.1, 1.1), QSizeF(0.1, 1.1), true, false);
+    row(QSizeF(qreal_min, 0.0), QSizeF(0.0, -qreal_min), true, true);
+}
+
+void tst_QSizeF::compare()
+{
+    QFETCH(QSizeF, lhs);
+    QFETCH(QSizeF, rhs);
+    QFETCH(bool, result);
+    QFETCH(bool, mixedResult);
+
+    QT_TEST_EQUALITY_OPS(lhs, rhs, result);
+
+    const QSize rhsFixed = rhs.toSize();
+    QT_TEST_EQUALITY_OPS(lhs, rhsFixed, mixedResult);
+}
+
 void tst_QSizeF::isNull_data()
 {
     QTest::addColumn<qreal>("width");