diff --git a/src/corelib/text/qlocale_tools.cpp b/src/corelib/text/qlocale_tools.cpp
index 52124672ca6..b68090365b8 100644
--- a/src/corelib/text/qlocale_tools.cpp
+++ b/src/corelib/text/qlocale_tools.cpp
@@ -810,10 +810,10 @@ QByteArray qdtoAscii(double d, QLocaleData::DoubleForm form, int precision, bool
 #if defined(QT_SUPPORTS_INT128) || (defined(Q_CC_MSVC) && (_MSC_VER >= 1930))
 static inline quint64 toUInt64(qinternaluint128 v)
 {
-#ifdef Q_CC_MSVC
-    return quint64(v._Word[0]);
-#else
+#ifdef QT_SUPPORTS_INT128
     return quint64(v);
+#elif defined(Q_CC_MSVC)
+    return quint64(v._Word[0]);
 #endif
 }
 QString quint128toBasicLatin(qinternaluint128 number, int base)
diff --git a/src/corelib/text/qlocale_tools_p.h b/src/corelib/text/qlocale_tools_p.h
index ef1e156f50b..9ae9dc8de74 100644
--- a/src/corelib/text/qlocale_tools_p.h
+++ b/src/corelib/text/qlocale_tools_p.h
@@ -18,13 +18,16 @@
 #include "qlocale_p.h"
 #include "qstring.h"
 
+#if !defined(QT_SUPPORTS_INT128) && defined(Q_CC_MSVC) && (_MSC_VER >= 1930)
+#include <__msvc_int128.hpp>
+#endif
+
 QT_BEGIN_NAMESPACE
 
 #if defined(QT_SUPPORTS_INT128)
 using qinternalint128 = qint128;
 using qinternaluint128 = quint128;
 #elif defined(Q_CC_MSVC) && (_MSC_VER >= 1930)
-#include <__msvc_int128.hpp>
 using qinternalint128 = std::_Signed128;
 using qinternaluint128 = std::_Unsigned128;
 #endif