diff --git a/src/corelib/itemmodels/qabstractitemmodel.cpp b/src/corelib/itemmodels/qabstractitemmodel.cpp
index 3d4d566d46c..3b929c8ec08 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.cpp
+++ b/src/corelib/itemmodels/qabstractitemmodel.cpp
@@ -34,7 +34,7 @@ QPersistentModelIndexData *QPersistentModelIndexData::create(const QModelIndex &
     Q_ASSERT(index.isValid()); // we will _never_ insert an invalid index in the list
     QPersistentModelIndexData *d = nullptr;
     QAbstractItemModel *model = const_cast<QAbstractItemModel *>(index.model());
-    QMultiHash<QModelIndex, QPersistentModelIndexData *> &indexes = model->d_func()->persistent.indexes;
+    QMultiHash<QtPrivate::QModelIndexWrapper, QPersistentModelIndexData *> &indexes = model->d_func()->persistent.indexes;
     const auto it = indexes.constFind(index);
     if (it != indexes.cend()) {
         d = (*it);
diff --git a/src/corelib/itemmodels/qabstractitemmodel_p.h b/src/corelib/itemmodels/qabstractitemmodel_p.h
index c2113fde9aa..d22a0a50823 100644
--- a/src/corelib/itemmodels/qabstractitemmodel_p.h
+++ b/src/corelib/itemmodels/qabstractitemmodel_p.h
@@ -37,6 +37,26 @@ public:
     static void destroy(QPersistentModelIndexData *data);
 };
 
+namespace QtPrivate {
+// This class is just a wrapper so we can use the fixed qHash() function for QModelIndex.
+struct QModelIndexWrapper // ### Qt 7: Remove again, use QModelIndex directly.
+{
+    QModelIndex index;
+    Q_IMPLICIT QModelIndexWrapper(const QModelIndex &i) : index(i) { }
+    Q_IMPLICIT inline operator QModelIndex() const { return index; }
+    friend bool operator==(const QModelIndexWrapper &l, const QModelIndexWrapper &r) { return l.index == r.index; }
+    friend bool operator!=(const QModelIndexWrapper &l, const QModelIndexWrapper &r) { return !(operator==(l,r)); }
+    friend bool operator==(const QModelIndexWrapper &l, const QModelIndex &r) { return l.index == r; }
+    friend bool operator!=(const QModelIndexWrapper &l, const QModelIndex &r) { return !(operator==(l.index,r)); }
+    friend bool operator==(const QModelIndex &l, const QModelIndexWrapper &r) { return l == r.index; }
+    friend bool operator!=(const QModelIndex &l, const QModelIndexWrapper &r) { return !(operator==(l,r.index)); }
+    friend inline size_t qHash(const QtPrivate::QModelIndexWrapper &index, size_t seed = 0) noexcept
+    {
+        return qHashMulti(seed, index.index.row(), index.index.column(), index.index.internalId());
+    }
+};
+}
+
 class Q_CORE_EXPORT QAbstractItemModelPrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QAbstractItemModel)
@@ -111,7 +131,7 @@ public:
 
     struct Persistent {
         Persistent() {}
-        QMultiHash<QModelIndex, QPersistentModelIndexData *> indexes;
+        QMultiHash<QtPrivate::QModelIndexWrapper, QPersistentModelIndexData *> indexes;
         QStack<QList<QPersistentModelIndexData *>> moved;
         QStack<QList<QPersistentModelIndexData *>> invalidated;
         void insertMultiAtEnd(const QModelIndex& key, QPersistentModelIndexData *data);
diff --git a/src/corelib/itemmodels/qsortfilterproxymodel.cpp b/src/corelib/itemmodels/qsortfilterproxymodel.cpp
index 73da00642a7..4076487d24a 100644
--- a/src/corelib/itemmodels/qsortfilterproxymodel.cpp
+++ b/src/corelib/itemmodels/qsortfilterproxymodel.cpp
@@ -126,7 +126,7 @@ public:
         QModelIndex source_parent;
     };
 
-    mutable QHash<QModelIndex, Mapping*> source_index_mapping;
+    mutable QHash<QtPrivate::QModelIndexWrapper, Mapping*> source_index_mapping;
 
     void setSortCaseSensitivityForwarder(Qt::CaseSensitivity cs)
     {
@@ -239,9 +239,9 @@ public:
 
     std::array<QMetaObject::Connection, 18> sourceConnections;
 
-    QHash<QModelIndex, Mapping *>::const_iterator create_mapping(
+    QHash<QtPrivate::QModelIndexWrapper, Mapping *>::const_iterator create_mapping(
         const QModelIndex &source_parent) const;
-    QHash<QModelIndex, Mapping *>::const_iterator create_mapping_recursive(
+    QHash<QtPrivate::QModelIndexWrapper, Mapping *>::const_iterator create_mapping_recursive(
             const QModelIndex &source_parent) const;
     QModelIndex proxy_to_source(const QModelIndex &proxyIndex) const;
     QModelIndex source_to_proxy(const QModelIndex &sourceIndex) const;
@@ -265,14 +265,14 @@ public:
         filter_regularexpression.setValueBypassingBindings(re);
     }
 
-    inline QHash<QModelIndex, Mapping *>::const_iterator index_to_iterator(
+    inline QHash<QtPrivate::QModelIndexWrapper, Mapping *>::const_iterator index_to_iterator(
         const QModelIndex &proxy_index) const
     {
         Q_ASSERT(proxy_index.isValid());
         Q_ASSERT(proxy_index.model() == q_func());
         const void *p = proxy_index.internalPointer();
         Q_ASSERT(p);
-        QHash<QModelIndex, Mapping *>::const_iterator it =
+        QHash<QtPrivate::QModelIndexWrapper, Mapping *>::const_iterator it =
                 source_index_mapping.constFind(static_cast<const Mapping*>(p)->source_parent);
         Q_ASSERT(it != source_index_mapping.constEnd());
         Q_ASSERT(it.value());
@@ -280,7 +280,7 @@ public:
     }
 
     inline QModelIndex create_index(int row, int column,
-                                    QHash<QModelIndex, Mapping*>::const_iterator it) const
+                                    QHash<QtPrivate::QModelIndexWrapper, Mapping*>::const_iterator it) const
     {
         return q_func()->createIndex(row, column, *it);
     }
@@ -382,7 +382,7 @@ public:
     bool recursiveParentAcceptsRow(const QModelIndex &source_parent) const;
 };
 
-typedef QHash<QModelIndex, QSortFilterProxyModelPrivate::Mapping *> IndexMap;
+typedef QHash<QtPrivate::QModelIndexWrapper, QSortFilterProxyModelPrivate::Mapping *> IndexMap;
 
 static bool operator&(QSortFilterProxyModelPrivate::Direction a, QSortFilterProxyModelPrivate::Direction b)
 {