diff --git a/src/widgets/styles/qstylesheetstyle.cpp b/src/widgets/styles/qstylesheetstyle.cpp
index 06a49d8e0ff..4c271996c5b 100644
--- a/src/widgets/styles/qstylesheetstyle.cpp
+++ b/src/widgets/styles/qstylesheetstyle.cpp
@@ -59,7 +59,7 @@
 #include <private/qstyleanimation_p.h>
 #endif
 #if QT_CONFIG(tabbar)
-#include <qtabbar.h>
+#include <private/qtabbar_p.h>
 #endif
 #include <QMetaProperty>
 #if QT_CONFIG(mainwindow)
@@ -3076,16 +3076,6 @@ void QStyleSheetStyle::unpolish(QApplication *app)
     styleSheetCaches->styleSheetCache.remove(qApp);
 }
 
-#if QT_CONFIG(tabbar)
-inline static bool verticalTabs(QTabBar::Shape shape)
-{
-    return shape == QTabBar::RoundedWest
-           || shape == QTabBar::RoundedEast
-           || shape == QTabBar::TriangularWest
-           || shape == QTabBar::TriangularEast;
-}
-#endif // QT_CONFIG(tabbar)
-
 void QStyleSheetStyle::drawComplexControl(ComplexControl cc, const QStyleOptionComplex *opt, QPainter *p,
                                           const QWidget *w) const
 {
diff --git a/src/widgets/widgets/qtabbar.cpp b/src/widgets/widgets/qtabbar.cpp
index ea408ec7f6a..da793126067 100644
--- a/src/widgets/widgets/qtabbar.cpp
+++ b/src/widgets/widgets/qtabbar.cpp
@@ -71,14 +71,6 @@ void QMovableTabWidget::paintEvent(QPaintEvent *e)
     p.drawPixmap(0, 0, m_pixmap);
 }
 
-inline static bool verticalTabs(QTabBar::Shape shape)
-{
-    return shape == QTabBar::RoundedWest
-           || shape == QTabBar::RoundedEast
-           || shape == QTabBar::TriangularWest
-           || shape == QTabBar::TriangularEast;
-}
-
 void QTabBarPrivate::updateMacBorderMetrics()
 {
 #if defined(Q_OS_MACOS)
diff --git a/src/widgets/widgets/qtabbar_p.h b/src/widgets/widgets/qtabbar_p.h
index a421836b93a..831d3acd3c5 100644
--- a/src/widgets/widgets/qtabbar_p.h
+++ b/src/widgets/widgets/qtabbar_p.h
@@ -245,6 +245,14 @@ public:
 
 };
 
+constexpr inline bool verticalTabs(QTabBar::Shape shape) noexcept
+{
+    return shape == QTabBar::RoundedWest
+            || shape == QTabBar::RoundedEast
+            || shape == QTabBar::TriangularWest
+            || shape == QTabBar::TriangularEast;
+}
+
 QT_END_NAMESPACE
 
 #endif