diff --git a/src/corelib/io/qfilesystemwatcher.cpp b/src/corelib/io/qfilesystemwatcher.cpp
index f40e166d9f..9b47b27f5c 100644
--- a/src/corelib/io/qfilesystemwatcher.cpp
+++ b/src/corelib/io/qfilesystemwatcher.cpp
@@ -352,33 +352,34 @@ QStringList QFileSystemWatcher::addPaths(const QStringList &paths)
         return QStringList();
     }
 
-    QFileSystemWatcherEngine *engine = 0;
+    const auto selectEngine = [this, d]() -> QFileSystemWatcherEngine* {
+#ifdef QT_BUILD_INTERNAL
+        const QString on = objectName();
 
-    const QString on = objectName();
-
-    if (!on.startsWith(QLatin1String("_qt_autotest_force_engine_"))) {
+        if (Q_UNLIKELY(on.startsWith(QLatin1String("_qt_autotest_force_engine_")))) {
+            // Autotest override case - use the explicitly selected engine only
+            const QStringRef forceName = on.midRef(26);
+            if (forceName == QLatin1String("poller")) {
+                qDebug("QFileSystemWatcher: skipping native engine, using only polling engine");
+                d_func()->initPollerEngine();
+                return d->poller;
+            } else if (forceName == QLatin1String("native")) {
+                qDebug("QFileSystemWatcher: skipping polling engine, using only native engine");
+                return d->native;
+            }
+            return nullptr;
+        }
+#endif
         // Normal runtime case - search intelligently for best engine
         if(d->native) {
-            engine = d->native;
+            return d->native;
         } else {
             d_func()->initPollerEngine();
-            engine = d->poller;
+            return d->poller;
         }
+    };
 
-    } else {
-        // Autotest override case - use the explicitly selected engine only
-        const QStringRef forceName = on.midRef(26);
-        if(forceName == QLatin1String("poller")) {
-            qDebug("QFileSystemWatcher: skipping native engine, using only polling engine");
-            d_func()->initPollerEngine();
-            engine = d->poller;
-        } else if(forceName == QLatin1String("native")) {
-            qDebug("QFileSystemWatcher: skipping polling engine, using only native engine");
-            engine = d->native;
-        }
-    }
-
-    if(engine)
+    if (auto engine = selectEngine())
         p = engine->addPaths(p, &d->files, &d->directories);
 
     return p;
diff --git a/tests/auto/corelib/io/qfilesystemwatcher/tst_qfilesystemwatcher.cpp b/tests/auto/corelib/io/qfilesystemwatcher/tst_qfilesystemwatcher.cpp
index 67ffa91e57..cdd1f6361e 100644
--- a/tests/auto/corelib/io/qfilesystemwatcher/tst_qfilesystemwatcher.cpp
+++ b/tests/auto/corelib/io/qfilesystemwatcher/tst_qfilesystemwatcher.cpp
@@ -46,11 +46,13 @@ public:
     tst_QFileSystemWatcher();
 
 private slots:
+#ifdef QT_BUILD_INTERNAL
     void basicTest_data();
     void basicTest();
 
     void watchDirectory_data();
     void watchDirectory();
+#endif
 
     void addPath();
     void removePath();
@@ -58,8 +60,10 @@ private slots:
     void removePaths();
     void removePathsFilesInSameDirectory();
 
+#ifdef QT_BUILD_INTERNAL
     void watchFileAndItsDirectory_data() { basicTest_data(); }
     void watchFileAndItsDirectory();
+#endif
 
     void nonExistingFile();
 
@@ -67,8 +71,10 @@ private slots:
 
     void destroyAfterQCoreApplication();
 
+#ifdef QT_BUILD_INTERNAL
     void QTBUG2331();
     void QTBUG2331_data() { basicTest_data(); }
+#endif
 
     void signalsEmittedAfterFileMoved();
 
@@ -90,6 +96,7 @@ tst_QFileSystemWatcher::tst_QFileSystemWatcher()
 #endif
 }
 
+#ifdef QT_BUILD_INTERNAL
 void tst_QFileSystemWatcher::basicTest_data()
 {
     QTest::addColumn<QString>("backend");
@@ -360,6 +367,7 @@ void tst_QFileSystemWatcher::watchDirectory()
     for (const auto &testDirName : testDirs)
         QVERIFY(temporaryDir.rmdir(testDirName));
 }
+#endif // QT_BUILD_INTERNAL
 
 void tst_QFileSystemWatcher::addPath()
 {
@@ -502,6 +510,7 @@ void tst_QFileSystemWatcher::removePathsFilesInSameDirectory()
     QCOMPARE(watcher.files().size(), 0);
 }
 
+#ifdef QT_BUILD_INTERNAL
 static QByteArray msgFileOperationFailed(const char *what, const QFile &f)
 {
     return what + QByteArrayLiteral(" failed on \"")
@@ -601,6 +610,7 @@ void tst_QFileSystemWatcher::watchFileAndItsDirectory()
 
     QVERIFY(temporaryDir.rmdir(testDirName));
 }
+#endif // QT_BUILD_INTERNAL
 
 void tst_QFileSystemWatcher::nonExistingFile()
 {
@@ -673,6 +683,7 @@ void tst_QFileSystemWatcher::destroyAfterQCoreApplication()
     QTest::qWait(30);
 }
 
+#ifdef QT_BUILD_INTERNAL
 // regression test for QTBUG2331.
 // essentially, on windows, directories were not unwatched after being deleted
 // from the disk, causing all sorts of interesting problems.
@@ -696,6 +707,7 @@ void tst_QFileSystemWatcher::QTBUG2331()
     QTRY_COMPARE(changedSpy.count(), 1);
     QCOMPARE(watcher.directories(), QStringList());
 }
+#endif // QT_BUILD_INTERNAL
 
 class SignalReceiver : public QObject
 {