diff --git a/src/corelib/io/qresource.cpp b/src/corelib/io/qresource.cpp
index 9f9cb0ab0bd..8c6a0fc6cef 100644
--- a/src/corelib/io/qresource.cpp
+++ b/src/corelib/io/qresource.cpp
@@ -1354,6 +1354,7 @@ private:
     uchar *map(qint64 offset, qint64 size, QFile::MemoryMapFlags flags);
     bool unmap(uchar *ptr);
     void uncompress() const;
+    void mapUncompressed();
     qint64 offset;
     QResource resource;
     mutable QByteArray uncompressed;
@@ -1577,7 +1578,6 @@ bool QResourceFileEngine::supportsExtension(Extension extension) const
 uchar *QResourceFileEnginePrivate::map(qint64 offset, qint64 size, QFile::MemoryMapFlags flags)
 {
     Q_Q(QResourceFileEngine);
-    Q_UNUSED(flags);
     Q_ASSERT_X(resource.compressionAlgorithm() == QResource::NoCompression
                || !uncompressed.isNull(), "QFile::map()",
                "open() should have uncompressed compressed resources");
@@ -1596,6 +1596,12 @@ uchar *QResourceFileEnginePrivate::map(qint64 offset, qint64 size, QFile::Memory
 
     // resource was not compressed
     address = resource.data();
+    if (flags & QFile::MapPrivateOption) {
+        // We need to provide read-write memory
+        mapUncompressed();
+        address = reinterpret_cast<const uchar *>(uncompressed.constData());
+    }
+
     return const_cast<uchar *>(address) + offset;
 }
 
@@ -1613,6 +1619,15 @@ void QResourceFileEnginePrivate::uncompress() const
     uncompressed = resource.uncompressedData();
 }
 
+void QResourceFileEnginePrivate::mapUncompressed()
+{
+    Q_ASSERT(resource.compressionAlgorithm() == QResource::NoCompression);
+    if (!uncompressed.isNull())
+        return;     // nothing to do
+    uncompressed = resource.uncompressedData();
+    uncompressed.detach();
+}
+
 #endif // !defined(QT_BOOTSTRAPPED)
 
 QT_END_NAMESPACE
diff --git a/tests/auto/corelib/io/qresourceengine/testqrc/test.qrc b/tests/auto/corelib/io/qresourceengine/testqrc/test.qrc
index f5e8c849a62..56972ea764a 100644
--- a/tests/auto/corelib/io/qresourceengine/testqrc/test.qrc
+++ b/tests/auto/corelib/io/qresourceengine/testqrc/test.qrc
@@ -9,10 +9,10 @@
         <file>searchpath1/search_file.txt</file>
         <file>searchpath2/search_file.txt</file>
         <file>search_file.txt</file>
-    </qresource>
-    <qresource><file>test/testdir.txt</file>
+        <file>test/testdir.txt</file>
         <file>otherdir/otherdir.txt</file>
         <file alias="aliasdir/aliasdir.txt">test/testdir2.txt</file>
+        <file alias="uncompresseddir/uncompressed.txt" compression-algorithm="none">aliasdir/compressme.txt</file>
         <file>test/test</file>
     </qresource>
     <qresource lang="ko">
@@ -21,7 +21,7 @@
     <qresource lang="de_CH">
         <file alias="aliasdir/aliasdir.txt" compress="9" threshold="30">aliasdir/compressme.txt</file>
     </qresource>
-    <qresource lang="de">
+    <qresource lang="de" compression-algorithm="none">
         <file alias="aliasdir/aliasdir.txt">test/german.txt</file>
     </qresource>
     <qresource prefix="withoutslashes">
diff --git a/tests/auto/corelib/io/qresourceengine/tst_qresourceengine.cpp b/tests/auto/corelib/io/qresourceengine/tst_qresourceengine.cpp
index 8c536949994..f5fb73b5183 100644
--- a/tests/auto/corelib/io/qresourceengine/tst_qresourceengine.cpp
+++ b/tests/auto/corelib/io/qresourceengine/tst_qresourceengine.cpp
@@ -180,6 +180,7 @@ void tst_QResourceEngine::checkStructure_data()
 #if defined(BUILTIN_TESTDATA)
                  << QLatin1String("testqrc")
 #endif
+                 << QLatin1String("uncompresseddir")
                  << QLatin1String("withoutslashes");
 
     QTest::newRow("root dir")          << QString(":/")
@@ -384,8 +385,16 @@ void tst_QResourceEngine::checkStructure_data()
         QFile file(QFINDTESTDATA("testqrc/aliasdir/compressme.txt"));
         file.open(QFile::ReadOnly);
         info = QFileInfo(QFINDTESTDATA("testqrc/aliasdir/compressme.txt"));
+        QByteArray compressmeContents = file.readAll();
         QTest::addRow("%s compressed text", qPrintable(root))   << QString(root + "aliasdir/aliasdir.txt")
-                                                  << file.readAll()
+                                                  << compressmeContents
+                                                  << QStringList()
+                                                  << QStringList()
+                                                  << QLocale("de_CH")
+                                                  << qlonglong(info.size());
+
+        QTest::addRow("%s non-compressed text", qPrintable(root))   << QString(root + "uncompresseddir/uncompressed.txt")
+                                                  << compressmeContents
                                                   << QStringList()
                                                   << QStringList()
                                                   << QLocale("de_CH")
@@ -463,6 +472,18 @@ void tst_QResourceEngine::checkStructure()
         // check that it is still valid after closing the file
         file.close();
         QCOMPARE(ba, contents);
+
+        // memory should be writable because we used MapPrivateOption
+        *ptr = '\0';
+
+        // but shouldn't affect the actual file or a new mapping
+        QFile file2(pathName);
+        QVERIFY(file2.open(QFile::ReadOnly));
+        QCOMPARE(file2.readAll(), contents);
+        ptr = file2.map(0, file.size(), QFile::MapPrivateOption);
+        QVERIFY2(ptr, qPrintable(file2.errorString()));
+        QByteArrayView bav(reinterpret_cast<const char *>(ptr), file.size());
+        QCOMPARE(bav, contents);
     }
     QLocale::setDefault(QLocale::system());
 }