diff --git a/src/corelib/text/qlatin1stringview.h b/src/corelib/text/qlatin1stringview.h
index 6b6c306b69b..257e7b30065 100644
--- a/src/corelib/text/qlatin1stringview.h
+++ b/src/corelib/text/qlatin1stringview.h
@@ -321,9 +321,6 @@ public:
 #endif // !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
 
 private:
-#if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
-    static inline int compare_helper(const QLatin1StringView &s1, const char *s2);
-#endif
     Q_ALWAYS_INLINE constexpr void verify(qsizetype pos, qsizetype n = 0) const
     {
         Q_ASSERT(pos >= 0);
@@ -331,6 +328,9 @@ private:
         Q_ASSERT(n >= 0);
         Q_ASSERT(n <= size() - pos);
     }
+    static int compare_helper(const QLatin1StringView &s1, const char *s2) noexcept
+    { return compare_helper(s1, s2, qstrlen(s2)); }
+    Q_CORE_EXPORT static int compare_helper(const QLatin1StringView &s1, const char *s2, qsizetype len) noexcept;
     Q_CORE_EXPORT static int compare_helper(const QChar *data1, qsizetype length1,
                                             QLatin1StringView s2,
                                             Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index 87f0cc2c485..46156669cfa 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -6452,6 +6452,18 @@ int QString::compare_helper(const QChar *data1, qsizetype length1, const char *d
   \overload compare()
 */
 
+/*!
+    \internal
+    \since 6.6
+*/
+int QLatin1StringView::compare_helper(const QLatin1StringView &s1, const char *s2, qsizetype len) noexcept
+{
+    // because qlatin1stringview.h can't include qutf8stringview.h
+    Q_ASSERT(len >= 0);
+    Q_ASSERT(s2 || len == 0);
+    return QtPrivate::compareStrings(s1, QUtf8StringView(s2, len));
+}
+
 /*!
     \internal
     \since 4.5
diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index 26fb4e44ca2..62eb64d7758 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -1177,12 +1177,6 @@ QT_ASCII_CAST_WARN inline bool QLatin1StringView::operator<=(const QByteArray &s
 QT_ASCII_CAST_WARN inline bool QLatin1StringView::operator>=(const QByteArray &s) const
 { return QString::fromUtf8(s) <= *this; }
 
-inline int QLatin1StringView::compare_helper(const QLatin1StringView &s1, const char *s2)
-{
-    return QString::compare(s1, QString::fromUtf8(s2));
-}
-
-
 QT_ASCII_CAST_WARN inline bool QString::operator==(const QByteArray &s) const
 { return QString::compare_helper(constData(), size(), s.constData(), s.size()) == 0; }
 QT_ASCII_CAST_WARN inline bool QString::operator!=(const QByteArray &s) const