diff --git a/src/gui/painting/qmatrix.cpp b/src/gui/painting/qmatrix.cpp
index 80a8f361d9..681490e347 100644
--- a/src/gui/painting/qmatrix.cpp
+++ b/src/gui/painting/qmatrix.cpp
@@ -244,11 +244,11 @@ QMatrix::QMatrix(qreal m11, qreal m12, qreal m21, qreal m22, qreal dx, qreal dy)
 {
 }
 
-
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
 /*!
      Constructs a matrix that is a copy of the given \a matrix.
  */
-QMatrix::QMatrix(const QMatrix &matrix)
+QMatrix::QMatrix(const QMatrix &matrix) Q_DECL_NOTHROW
     : _m11(matrix._m11)
     , _m12(matrix._m12)
     , _m21(matrix._m21)
@@ -257,6 +257,7 @@ QMatrix::QMatrix(const QMatrix &matrix)
     , _dy(matrix._dy)
 {
 }
+#endif
 
 /*!
     Sets the matrix elements to the specified values, \a m11, \a m12,
@@ -1063,10 +1064,11 @@ QMatrix QMatrix::operator *(const QMatrix &m) const
     return QMatrix(tm11, tm12, tm21, tm22, tdx, tdy, true);
 }
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
 /*!
     Assigns the given \a matrix's values to this matrix.
 */
-QMatrix &QMatrix::operator=(const QMatrix &matrix)
+QMatrix &QMatrix::operator=(const QMatrix &matrix) Q_DECL_NOTHROW
 {
     _m11 = matrix._m11;
     _m12 = matrix._m12;
@@ -1076,6 +1078,7 @@ QMatrix &QMatrix::operator=(const QMatrix &matrix)
     _dy  = matrix._dy;
     return *this;
 }
+#endif
 
 /*!
     \since 4.2
diff --git a/src/gui/painting/qmatrix.h b/src/gui/painting/qmatrix.h
index 342898b561..b28c8433cd 100644
--- a/src/gui/painting/qmatrix.h
+++ b/src/gui/painting/qmatrix.h
@@ -60,7 +60,16 @@ public:
     QMatrix();
     QMatrix(qreal m11, qreal m12, qreal m21, qreal m22,
             qreal dx, qreal dy);
-    QMatrix(const QMatrix &matrix);
+
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    // ### Qt 6: remove; the compiler-generated ones are fine!
+    QMatrix &operator=(QMatrix &&other) Q_DECL_NOTHROW // = default
+    { memcpy(this, &other, sizeof(QMatrix)); return *this; }
+    QMatrix &operator=(const QMatrix &) Q_DECL_NOTHROW; // = default
+    QMatrix(QMatrix &&other) Q_DECL_NOTHROW // = default
+    { memcpy(this, &other, sizeof(QMatrix)); }
+    QMatrix(const QMatrix &other) Q_DECL_NOTHROW; // = default
+#endif
 
     void setMatrix(qreal m11, qreal m12, qreal m21, qreal m22,
                    qreal dx, qreal dy);
@@ -106,8 +115,6 @@ public:
     QMatrix &operator*=(const QMatrix &);
     QMatrix operator*(const QMatrix &o) const;
 
-    QMatrix &operator=(const QMatrix &);
-
     operator QVariant() const;
 
 private:
diff --git a/src/gui/painting/qtransform.cpp b/src/gui/painting/qtransform.cpp
index 3e2a002148..a0596d1a07 100644
--- a/src/gui/painting/qtransform.cpp
+++ b/src/gui/painting/qtransform.cpp
@@ -1011,10 +1011,11 @@ QTransform QTransform::operator*(const QTransform &m) const
     element of this matrix.
 */
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
 /*!
     Assigns the given \a matrix's values to this matrix.
 */
-QTransform & QTransform::operator=(const QTransform &matrix)
+QTransform & QTransform::operator=(const QTransform &matrix) Q_DECL_NOTHROW
 {
     affine._m11 = matrix.affine._m11;
     affine._m12 = matrix.affine._m12;
@@ -1030,6 +1031,7 @@ QTransform & QTransform::operator=(const QTransform &matrix)
 
     return *this;
 }
+#endif
 
 /*!
     Resets the matrix to an identity matrix, i.e. all elements are set
diff --git a/src/gui/painting/qtransform.h b/src/gui/painting/qtransform.h
index 8e97d1eb6f..470a5565e1 100644
--- a/src/gui/painting/qtransform.h
+++ b/src/gui/painting/qtransform.h
@@ -74,6 +74,19 @@ public:
                qreal h22, qreal dx, qreal dy);
     explicit QTransform(const QMatrix &mtx);
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    // ### Qt 6: remove; the compiler-generated ones are fine!
+    QTransform &operator=(QTransform &&other) Q_DECL_NOTHROW // = default
+    { memcpy(this, &other, sizeof(QTransform)); return *this; }
+    QTransform &operator=(const QTransform &) Q_DECL_NOTHROW; // = default
+    QTransform(QTransform &&other) Q_DECL_NOTHROW // = default
+        : affine(Qt::Uninitialized)
+    { memcpy(this, &other, sizeof(QTransform)); }
+    QTransform(const QTransform &other) Q_DECL_NOTHROW // = default
+        : affine(Qt::Uninitialized)
+    { memcpy(this, &other, sizeof(QTransform)); }
+#endif
+
     bool isAffine() const;
     bool isIdentity() const;
     bool isInvertible() const;
@@ -124,8 +137,6 @@ public:
     QTransform &operator*=(const QTransform &);
     QTransform operator*(const QTransform &o) const;
 
-    QTransform &operator=(const QTransform &);
-
     operator QVariant() const;
 
     void reset();
@@ -180,9 +191,10 @@ private:
 
     mutable uint m_type : 5;
     mutable uint m_dirty : 5;
-
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     class Private;
     Private *d;
+#endif
 };
 Q_DECLARE_TYPEINFO(QTransform, Q_MOVABLE_TYPE);