diff --git a/tests/auto/corelib/text/qstringbuilder/CMakeLists.txt b/tests/auto/corelib/text/qstringbuilder/CMakeLists.txt
index 2f6cc8beef3..6ce4c5c629b 100644
--- a/tests/auto/corelib/text/qstringbuilder/CMakeLists.txt
+++ b/tests/auto/corelib/text/qstringbuilder/CMakeLists.txt
@@ -6,3 +6,4 @@ add_subdirectory(qstringbuilder2)
 add_subdirectory(qstringbuilder3)
 add_subdirectory(qstringbuilder4)
 add_subdirectory(qstringbuilder5)
+add_subdirectory(qstringbuilder6)
diff --git a/tests/auto/corelib/text/qstringbuilder/qstringbuilder1/stringbuilder.cpp b/tests/auto/corelib/text/qstringbuilder/qstringbuilder1/stringbuilder.cpp
index a845e21138b..d929b5b58dc 100644
--- a/tests/auto/corelib/text/qstringbuilder/qstringbuilder1/stringbuilder.cpp
+++ b/tests/auto/corelib/text/qstringbuilder/qstringbuilder1/stringbuilder.cpp
@@ -479,6 +479,18 @@ void runScenario()
     r = QByteArrayLiteral(LITERAL) P string;
     QCOMPARE(r, r2);
 
+#ifndef HAS_QTBUG_127928
+    r = ba P l1string;
+    QCOMPARE(r, r2);
+    r = l1string P ba;
+    QCOMPARE(r, r2);
+
+    r = ba P QLatin1String(l1string);
+    QCOMPARE(r, r2);
+    r = QLatin1String(l1string) P std::as_const(ba);
+    QCOMPARE(r, r2);
+#endif
+
     static const char badata[] = LITERAL_EXTRA;
     ba = QByteArray::fromRawData(badata, LITERAL_LEN);
     r = ba P string;
diff --git a/tests/auto/corelib/text/qstringbuilder/qstringbuilder6/CMakeLists.txt b/tests/auto/corelib/text/qstringbuilder/qstringbuilder6/CMakeLists.txt
new file mode 100644
index 00000000000..6a3230e1c0f
--- /dev/null
+++ b/tests/auto/corelib/text/qstringbuilder/qstringbuilder6/CMakeLists.txt
@@ -0,0 +1,17 @@
+# Copyright (C) 2024 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+#####################################################################
+## tst_qstringbuilder6 Test:
+#####################################################################
+
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_qstringbuilder6 LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
+qt_internal_add_test(tst_qstringbuilder6
+    SOURCES
+        tst_qstringbuilder6.cpp
+)
diff --git a/tests/auto/corelib/text/qstringbuilder/qstringbuilder6/tst_qstringbuilder6.cpp b/tests/auto/corelib/text/qstringbuilder/qstringbuilder6/tst_qstringbuilder6.cpp
new file mode 100644
index 00000000000..5393ec2b905
--- /dev/null
+++ b/tests/auto/corelib/text/qstringbuilder/qstringbuilder6/tst_qstringbuilder6.cpp
@@ -0,0 +1,41 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#include <QtCore/qglobal.h>
+
+// SCENARIO 6
+// We disable QStringBuilder and compile with normal operator+ to verify
+// that all QSB supported operations are still available when QSB is disabled.
+// We also allow casts to/from ASCII
+#undef QT_USE_QSTRINGBUILDER
+#undef QT_NO_CAST_FROM_ASCII
+#undef QT_NO_CAST_TO_ASCII
+
+#include <QtCore/QObject>
+#include <QtCore/QString>
+#include <QtCore/QStringBuilder>
+#include <QtTest/QTest>
+
+#include <QtCore/q20iterator.h>
+
+#define LITERAL "some literal"
+
+#define HAS_QTBUG_127928    1
+
+namespace {
+#define P +
+#include "../qstringbuilder1/stringbuilder.cpp"
+#undef P
+} // namespace
+
+class tst_QStringBuilder6 : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void scenario() { runScenario(); }
+};
+
+#include "tst_qstringbuilder6.moc"
+
+QTEST_APPLESS_MAIN(tst_QStringBuilder6)