diff --git a/src/corelib/text/qlocale_tools.cpp b/src/corelib/text/qlocale_tools.cpp
index b68090365b8..6b04bc92cd1 100644
--- a/src/corelib/text/qlocale_tools.cpp
+++ b/src/corelib/text/qlocale_tools.cpp
@@ -807,15 +807,16 @@ QByteArray qdtoAscii(double d, QLocaleData::DoubleForm form, int precision, bool
     return dtoString<QByteArray>(d, form, precision, uppercase);
 }
 
-#if defined(QT_SUPPORTS_INT128) || (defined(Q_CC_MSVC) && (_MSC_VER >= 1930))
+#if defined(QT_SUPPORTS_INT128) || defined(QT_USE_MSVC_INT128)
 static inline quint64 toUInt64(qinternaluint128 v)
 {
-#ifdef QT_SUPPORTS_INT128
-    return quint64(v);
-#elif defined(Q_CC_MSVC)
+#if defined(QT_USE_MSVC_INT128)
     return quint64(v._Word[0]);
+#else
+    return quint64(v);
 #endif
 }
+
 QString quint128toBasicLatin(qinternaluint128 number, int base)
 {
     // We divide our 128-bit number into parts that we can do text
@@ -879,6 +880,6 @@ QString qint128toBasicLatin(qinternalint128 number, int base)
         result.prepend(u'-');
     return result;
 }
-#endif // defined(QT_SUPPORTS_INT128) || (defined(Q_CC_MSVC) && (_MSC_VER >= 1930))
+#endif // defined(QT_SUPPORTS_INT128) || defined(QT_USE_MSVC_INT128)
 
 QT_END_NAMESPACE
diff --git a/src/corelib/text/qlocale_tools_p.h b/src/corelib/text/qlocale_tools_p.h
index 9ae9dc8de74..2cfe25d2997 100644
--- a/src/corelib/text/qlocale_tools_p.h
+++ b/src/corelib/text/qlocale_tools_p.h
@@ -18,8 +18,9 @@
 #include "qlocale_p.h"
 #include "qstring.h"
 
-#if !defined(QT_SUPPORTS_INT128) && defined(Q_CC_MSVC) && (_MSC_VER >= 1930)
+#if !defined(QT_SUPPORTS_INT128) && (defined(Q_CC_MSVC) && (_MSC_VER >= 1930) && __has_include(<__msvc_int128.hpp>))
 #include <__msvc_int128.hpp>
+#define QT_USE_MSVC_INT128
 #endif
 
 QT_BEGIN_NAMESPACE
@@ -27,7 +28,7 @@ QT_BEGIN_NAMESPACE
 #if defined(QT_SUPPORTS_INT128)
 using qinternalint128 = qint128;
 using qinternaluint128 = quint128;
-#elif defined(Q_CC_MSVC) && (_MSC_VER >= 1930)
+#elif defined(QT_USE_MSVC_INT128)
 using qinternalint128 = std::_Signed128;
 using qinternaluint128 = std::_Unsigned128;
 #endif
@@ -55,7 +56,7 @@ void qt_doubleToAscii(double d, QLocaleData::DoubleForm form, int precision,
 [[nodiscard]] QByteArray qdtoAscii(double d, QLocaleData::DoubleForm form,
                                    int precision, bool uppercase);
 
-#if defined(QT_SUPPORTS_INT128) || (defined(Q_CC_MSVC) && (_MSC_VER >= 1930))
+#if defined(QT_SUPPORTS_INT128) || defined(QT_USE_MSVC_INT128)
 [[nodiscard]] Q_CORE_EXPORT QString quint128toBasicLatin(qinternaluint128 number,
                                                          int base = 10);
 [[nodiscard]] Q_CORE_EXPORT QString qint128toBasicLatin(qinternalint128 number,