diff --git a/src/gui/kernel/qplatformthemefactory_p.h b/src/gui/kernel/qplatformthemefactory_p.h
index 3f77f03485..c312eadf27 100644
--- a/src/gui/kernel/qplatformthemefactory_p.h
+++ b/src/gui/kernel/qplatformthemefactory_p.h
@@ -59,7 +59,7 @@ QT_BEGIN_NAMESPACE
 
 class QPlatformTheme;
 
-class QPlatformThemeFactory
+class Q_GUI_EXPORT QPlatformThemeFactory
 {
 public:
     static QStringList keys(const QString &platformPluginPath = QString());