diff --git a/core/libs/database/history/itemhistorygraphdata.h b/core/libs/database/history/itemhistorygraphdata.h
index ee00fd613d..4411a3cff1 100644
--- a/core/libs/database/history/itemhistorygraphdata.h
+++ b/core/libs/database/history/itemhistorygraphdata.h
@@ -1,157 +1,157 @@
 /* ============================================================
  *
  * This file is a part of digiKam project
  * https://www.digikam.org
  *
  * Date        : 2010-10-23
  * Description : Graph data class for item history
  *
  * Copyright (C) 2010-2011 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
  *
  * This program is free software; you can redistribute it
  * and/or modify it under the terms of the GNU General
  * Public License as published by the Free Software Foundation;
  * either version 2, or (at your option)
  * any later version.
  *
  * This program 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 General Public License for more details.
  *
  * ============================================================ */
 
 #ifndef DIGIKAM_ITEM_HISTORY_GRAPH_DATA_H
 #define DIGIKAM_ITEM_HISTORY_GRAPH_DATA_H
 
 // Qt includes
 
 #include <QSharedData>
 
 // Local includes
 
 #include "filteraction.h"
 #include "historyimageid.h"
 #include "itemhistorygraph_boost.h"
 
 namespace Digikam
 {
 
 class ItemInfo;
 
 /**
  * Every vertex has one associated object of this class
  *
  * All entries in a vertex refer to _identical_ images.
  * There can be multiple referred images in a history entry.
  * Each single HistoryImageId can resolve into none, one,
  * or multiple ItemInfos.
  * So there is no mapping between the two fields here.
  *
  * If an image is created from multiple source images (panorama etc.),
  * there will be one vertex per source image!
  */
-class HistoryVertexProperties
+class DIGIKAM_DATABASE_EXPORT HistoryVertexProperties
 {
 public:
 
     ItemInfo firstItemInfo()                    const;
 
     bool markedAs(HistoryImageId::Type)         const;
     bool alwaysMarkedAs(HistoryImageId::Type)   const;
 
     bool operator==(const QString& uuid)        const;
     bool operator==(const ItemInfo& info)       const;
     bool operator==(qlonglong id)               const;
     bool operator==(const HistoryImageId& info) const;
 
     HistoryVertexProperties& operator+=(const QString& uuid);
     HistoryVertexProperties& operator+=(const ItemInfo& info);
     HistoryVertexProperties& operator+=(const HistoryImageId& info);
 
 public:
 
     QString               uuid;
     QList<HistoryImageId> referredImages;
     QList<ItemInfo>       infos;
 };
 
 QDebug operator<<(QDebug dbg, const HistoryVertexProperties& props);
 QDebug operator<<(QDebug dbg, const HistoryImageId& id);
 
 // ------------------------------------------------------------------------------
 
 /**
  * Every edge has one associated object of this class.
  *
  * For two vertices v1, v2 with and edge e, v1 -> v2,
  * describes the actions necessary to create v2 from v2:
  * v1 -> actions[0] -> ... -> actions[n] = v2.
  */
-class HistoryEdgeProperties
+class DIGIKAM_DATABASE_EXPORT HistoryEdgeProperties
 {
 public:
 
     QList<FilterAction> actions;
 
     HistoryEdgeProperties& operator+=(const FilterAction& action);
 };
 
 typedef Graph<HistoryVertexProperties, HistoryEdgeProperties> HistoryGraph;
 
 // ------------------------------------------------------------------------------
 
-class ItemHistoryGraphData : public HistoryGraph,
-                             public QSharedData
+class DIGIKAM_DATABASE_EXPORT ItemHistoryGraphData : public HistoryGraph,
+                                                     public QSharedData
 {
 public:
 
     ItemHistoryGraphData()
         : HistoryGraph(ChildToParent)
     {
     }
 
     explicit ItemHistoryGraphData(const HistoryGraph& g)
         : HistoryGraph(g)
     {
     }
 
     ItemHistoryGraphData& operator=(const HistoryGraph& g)
     {
         HistoryGraph::operator=(g);
 
         return *this;
     }
 
     Vertex addVertex(const HistoryImageId& id);
     Vertex addVertex(const QList<HistoryImageId>& imageIds);
     Vertex addVertex(qlonglong id);
     Vertex addVertexScanned(qlonglong id);
     Vertex addVertex(const ItemInfo& info);
 
     void addHistory(const DImageHistory& givenHistory, qlonglong extraCurrent = 0);
 
     int removeNextUnresolvedVertex(int begin);
 
     inline QList<ItemInfo> toInfoList(const QList<Vertex>& vertices) const
     {
         QList<ItemInfo> infos;
 
         foreach (const HistoryGraph::Vertex& v, vertices)
         {
             infos << properties(v).infos;
         }
 
         return infos;
     }
 
     QHash<Vertex, HistoryImageId::Types> categorize() const;
 
 protected:
 
     void applyProperties(Vertex& v, const QList<ItemInfo>& infos, const QList<HistoryImageId>& ids);
 };
 
 } // namespace Digikam
 
 #endif // DIGIKAM_ITEM_HISTORY_GRAPH_DATA_H