diff --git a/src/corelib/compat/removed_api.cpp b/src/corelib/compat/removed_api.cpp
index 566c7b608b5..61d3842e64d 100644
--- a/src/corelib/compat/removed_api.cpp
+++ b/src/corelib/compat/removed_api.cpp
@@ -113,7 +113,41 @@ QByteArray QtPrivate::QByteArrayList_join(const QByteArrayList *that, const char
     return QByteArrayList_join(that, {sep, seplen});
 }
 
+#endif // QT_REMOVED_SINCE(6, 3)
+#if QT_REMOVED_SINCE(6, 4)
+
+#include "qversionnumber.h"
+
+#  if QT_POINTER_SIZE != 4
+QVersionNumber QVersionNumber::fromString(const QString &string, int *suffixIndex)
+{
+    qsizetype si;
+    QVersionNumber r = fromString(QLatin1String(string.toLatin1()), &si);
+    if (suffixIndex)
+        *suffixIndex = si;
+    return r;
+}
+
+QVersionNumber QVersionNumber::fromString(QStringView string, int *suffixIndex)
+{
+    qsizetype si;
+    QVersionNumber r = fromString(QLatin1String(string.toLatin1()), &si);
+    if (suffixIndex)
+        *suffixIndex = si;
+    return r;
+}
+
+QVersionNumber QVersionNumber::fromString(QLatin1String string, int *suffixIndex)
+{
+    qsizetype si;
+    QVersionNumber r = fromString(string, &si);
+    if (suffixIndex)
+        *suffixIndex = si;
+    return r;
+}
+#  endif // QT_POINTER_SIZE != 4
+
 // #include <qotherheader.h>
 // // implement removed functions from qotherheader.h
 
-#endif // QT_REMOVED_SINCE(6, 3)
+#endif // QT_REMOVED_SINCE(6, 4)
diff --git a/src/corelib/tools/qversionnumber.cpp b/src/corelib/tools/qversionnumber.cpp
index 54524c44055..d30608534fa 100644
--- a/src/corelib/tools/qversionnumber.cpp
+++ b/src/corelib/tools/qversionnumber.cpp
@@ -413,7 +413,7 @@ QString QVersionNumber::toString() const
 
     \sa isNull()
 */
-QVersionNumber QVersionNumber::fromString(const QString &string, int *suffixIndex)
+QVersionNumber QVersionNumber::fromString(const QString &string, qsizetype *suffixIndex)
 {
     return fromString(QLatin1String(string.toLatin1()), suffixIndex);
 }
@@ -434,7 +434,7 @@ QVersionNumber QVersionNumber::fromString(const QString &string, int *suffixInde
 
     \sa isNull()
 */
-QVersionNumber QVersionNumber::fromString(QStringView string, int *suffixIndex)
+QVersionNumber QVersionNumber::fromString(QStringView string, qsizetype *suffixIndex)
 {
     return fromString(QLatin1String(string.toLatin1()), suffixIndex);
 }
@@ -454,7 +454,7 @@ QVersionNumber QVersionNumber::fromString(QStringView string, int *suffixIndex)
 
     \sa isNull()
 */
-QVersionNumber QVersionNumber::fromString(QLatin1String string, int *suffixIndex)
+QVersionNumber QVersionNumber::fromString(QLatin1String string, qsizetype *suffixIndex)
 {
     QList<int> seg;
 
@@ -474,7 +474,7 @@ QVersionNumber QVersionNumber::fromString(QLatin1String string, int *suffixIndex
     } while (start < endOfString && (end < endOfString && *end == '.'));
 
     if (suffixIndex)
-        *suffixIndex = int(lastGoodEnd - string.begin());
+        *suffixIndex = lastGoodEnd - string.begin();
 
     return QVersionNumber(std::move(seg));
 }
diff --git a/src/corelib/tools/qversionnumber.h b/src/corelib/tools/qversionnumber.h
index 9d6c7d30181..175abe4e61c 100644
--- a/src/corelib/tools/qversionnumber.h
+++ b/src/corelib/tools/qversionnumber.h
@@ -276,10 +276,16 @@ public:
 
     [[nodiscard]] Q_CORE_EXPORT QString toString() const;
 #if QT_STRINGVIEW_LEVEL < 2
-    [[nodiscard]] Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(const QString &string, int *suffixIndex = nullptr);
+    [[nodiscard]] Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(const QString &string, qsizetype *suffixIndex = nullptr);
+#endif
+    [[nodiscard]] Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QLatin1String string, qsizetype *suffixIndex = nullptr);
+    [[nodiscard]] Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QStringView string, qsizetype *suffixIndex = nullptr);
+
+#if QT_REMOVED_SINCE(6, 4) && QT_POINTER_SIZE != 4
+    [[nodiscard]] Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(const QString &string, int *suffixIndex);
+    [[nodiscard]] Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QLatin1String string, int *suffixIndex);
+    [[nodiscard]] Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QStringView string, int *suffixIndex);
 #endif
-    [[nodiscard]] Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QLatin1String string, int *suffixIndex = nullptr);
-    [[nodiscard]] Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QStringView string, int *suffixIndex = nullptr);
 
     [[nodiscard]] friend bool operator> (const QVersionNumber &lhs, const QVersionNumber &rhs) noexcept
     { return compare(lhs, rhs) > 0; }
diff --git a/tests/auto/corelib/tools/qversionnumber/tst_qversionnumber.cpp b/tests/auto/corelib/tools/qversionnumber/tst_qversionnumber.cpp
index b0dbcb042de..35c5dec36e1 100644
--- a/tests/auto/corelib/tools/qversionnumber/tst_qversionnumber.cpp
+++ b/tests/auto/corelib/tools/qversionnumber/tst_qversionnumber.cpp
@@ -511,7 +511,7 @@ void tst_QVersionNumber::fromString()
     QFETCH(QVersionNumber, expectedVersion);
     QFETCH(int, suffixIndex);
 
-    int index;
+    qsizetype index;
     QCOMPARE(QVersionNumber::fromString(constructionString), expectedVersion);
     QCOMPARE(QVersionNumber::fromString(constructionString, &index), expectedVersion);
     QCOMPARE(index, suffixIndex);