diff --git a/src/windowsystem/windoweffects.h b/src/windowsystem/windoweffects.h
index 2814111..f09c9b5 100644
--- a/src/windowsystem/windoweffects.h
+++ b/src/windowsystem/windoweffects.h
@@ -1,75 +1,76 @@
 /*
  * Copyright 2014 Martin Gräßlin <mgraesslin@kde.org>
  * Copyright 2015 Marco Martin <mart@kde.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) version 3, or any
  * later version accepted by the membership of KDE e.V. (or its
  * successor approved by the membership of KDE e.V.), which shall
  * act as a proxy defined in Section 6 of version 3 of the license.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 #ifndef WINDOWEFFECTS_H
 #define WINDOWEFFECTS_H
 #include <KWindowSystem/private/kwindoweffects_p.h>
 
+#include <QHash>
 
 namespace KWayland
 {
     namespace Client
     {
         class BlurManager;
         class ContrastManager;
         class Compositor;
         class ConnectionThread;
     }
 }
 
 class WindowEffects : public QObject, public KWindowEffectsPrivate
 {
     Q_OBJECT
 public:
     WindowEffects();
     ~WindowEffects() override;
 
     static QWindow *windowForId(WId);
 
     bool eventFilter(QObject *watched, QEvent *event) override;
     void trackWindow(QWindow *window);
     void releaseWindow(QWindow *window);
 
     bool isEffectAvailable(KWindowEffects::Effect effect) override;
     void slideWindow(WId id, KWindowEffects::SlideFromLocation location, int offset) override;
     void slideWindow(QWidget *widget, KWindowEffects::SlideFromLocation location) override;
     QList<QSize> windowSizes(const QList<WId> &ids) override;
     void presentWindows(WId controller, const QList<WId> &ids) override;
     void presentWindows(WId controller, int desktop = NET::OnAllDesktops) override;
     void highlightWindows(WId controller, const QList<WId> &ids) override;
     void enableBlurBehind(WId winId, bool enable = true, const QRegion &region = QRegion()) override;
     void enableBlurBehind(QWindow *window, bool enable, const QRegion &region);
     void enableBackgroundContrast(WId winId, bool enable = true, qreal contrast = 1, qreal intensity = 1, qreal saturation = 1, const QRegion &region = QRegion()) override;
     void enableBackgroundContrast(QWindow *window, bool enable = true, qreal contrast = 1, qreal intensity = 1, qreal saturation = 1, const QRegion &region = QRegion());
     void markAsDashboard(WId window) override;
 private:
     QHash<QWindow *, QMetaObject::Connection> m_windowWatchers;
     QHash<QWindow *, QRegion> m_blurRegions;
     struct BackgroundContrastData {
         qreal contrast = 1;
         qreal intensity = 1;
         qreal saturation = 1;
         QRegion region;
     };
     QHash<QWindow *, BackgroundContrastData> m_backgroundConstrastRegions;
 
 };
 
 #endif