diff --git a/src/database/board.h b/src/database/board.h
index 93f6bdfac..269dcbe70 100644
--- a/src/database/board.h
+++ b/src/database/board.h
@@ -20,7 +20,6 @@
 #include "bitboard.h"
 
 #include <QString>
-#include <QStack>
 
 #define COMPILED_GUESS_FILE_ID ((quint32)0xCD5CBD03U)
 
diff --git a/src/database/common.h b/src/database/common.h
index 185a5619d..a5e2b722f 100644
--- a/src/database/common.h
+++ b/src/database/common.h
@@ -11,7 +11,6 @@
 #ifndef __COMMON_H__
 #define __COMMON_H__
 
-#include <QtDebug>
 #include <QMap>
 #include <QString>
 #include <QStringList>
diff --git a/src/database/database.h b/src/database/database.h
index 126d50532..fb50936fa 100644
--- a/src/database/database.h
+++ b/src/database/database.h
@@ -11,15 +11,13 @@
 #ifndef __DATABASE_H__
 #define __DATABASE_H__
 
-#include <QString>
-#include <QTextStream>
-
 #include "filter.h"
 #include "game.h"
-#include "search.h"
-#include "query.h"
 #include "index.h"
-#include "QMutex"
+
+#include <QMutex>
+#include <QString>
+#include <QTextStream>
 
 /** @defgroup Database Database - classes to manipulate chess game files*/
 
@@ -27,10 +25,6 @@
    The Database class is abstract, providing a common interface for all
    database types. There are methods for the loading and saving of games,
    and for performing searches and queries.
-
-   @todo
-   Add name() to get just the database name
-   Add isReadOnly()
 */
 
 class Database : public QObject
@@ -72,7 +66,7 @@ class Database : public QObject
     /** Loads only moves into a game from the given position */
     virtual void loadGameMoves(GameId index, Game& game) = 0;
     /** Saves a game at the given position, returns true if successful */
-    virtual bool replace(GameId , Game&);
+    virtual bool replace(GameId, Game&);
     /** Adds a game to the database */
     virtual bool appendGame(const Game&);
     /** Removes a game from the database */
diff --git a/src/database/enginelist.h b/src/database/enginelist.h
index 507902f36..d6a7a7f62 100644
--- a/src/database/enginelist.h
+++ b/src/database/enginelist.h
@@ -13,7 +13,6 @@
 #include <QtCore>
 #include "enginedata.h"
 
-
 /** The EngineList class contains configuration of all installed engines. */
 class EngineList : public QList<EngineData>
 {
diff --git a/src/database/engineoptiondata.h b/src/database/engineoptiondata.h
index 95d996306..91c38c4ad 100644
--- a/src/database/engineoptiondata.h
+++ b/src/database/engineoptiondata.h
@@ -4,6 +4,7 @@
 
 #ifndef ENGINEOPTIONDATA_H
 #define ENGINEOPTIONDATA_H
+
 #include <QtCore>
 #include <QList>
 #include <QMap>
diff --git a/src/database/filter.h b/src/database/filter.h
index 6ef9191bf..dc49dbec7 100644
--- a/src/database/filter.h
+++ b/src/database/filter.h
@@ -17,8 +17,6 @@
 #include <QThread>
 
 #include "common.h"
-#include "search.h"
-#include "query.h"
 #include "tristatetree.h"
 
 class Database;
diff --git a/src/database/index.h b/src/database/index.h
index 6e883bf93..7ac314f28 100644
--- a/src/database/index.h
+++ b/src/database/index.h
@@ -17,7 +17,6 @@
 #include <QObject>
 
 #include "indexitem.h"
-#include "search.h"
 #include "game.h"
 
 /** @ingroup Database
diff --git a/src/database/openingtree.cpp b/src/database/openingtree.cpp
index e88761442..f6b21d5e6 100644
--- a/src/database/openingtree.cpp
+++ b/src/database/openingtree.cpp
@@ -12,6 +12,7 @@
 #include "openingtree.h"
 #include "settings.h"
 #include "movedata.h"
+#include "openingtreethread.h"
 
 #include <QIcon>
 #include <QImage>
diff --git a/src/database/openingtree.h b/src/database/openingtree.h
index 810d0cec0..6ea749c70 100644
--- a/src/database/openingtree.h
+++ b/src/database/openingtree.h
@@ -10,11 +10,11 @@
 #ifndef __OPENINGTREE_H__
 #define __OPENINGTREE_H__
 
+#include "movedata.h"
+
 #include <QAbstractTableModel>
 
-#include "filter.h"
-#include "game.h"
-#include "openingtreethread.h"
+class Filter;
 
 /** @ingroup Search
 The OpeningTree class is a class to calculate opening tree for given position. */
diff --git a/src/database/query.h b/src/database/query.h
index d65dcc7c6..24749e08a 100644
--- a/src/database/query.h
+++ b/src/database/query.h
@@ -11,7 +11,6 @@
 
 #ifndef __QUERY_H__
 #define __QUERY_H__
-class Search;
 
 #include "search.h"
 #include <QList>
diff --git a/src/database/tablebase.h b/src/database/tablebase.h
index 14c816e39..0bd89bf70 100644
--- a/src/database/tablebase.h
+++ b/src/database/tablebase.h
@@ -13,7 +13,6 @@
 
 #include <QNetworkAccessManager>
 
-#include "common.h"
 #include "move.h"
 
 class QNetworkReply;
diff --git a/src/database/tristatetree.h b/src/database/tristatetree.h
index 8c233ce14..6b3d81bcf 100644
--- a/src/database/tristatetree.h
+++ b/src/database/tristatetree.h
@@ -11,7 +11,6 @@
 #ifndef __TRISTATETREE_H__
 #define __TRISTATETREE_H__
 
-#include "search.h"
 #include "query.h"
 
 /** @ingroup Search
diff --git a/src/database/uciengine.h b/src/database/uciengine.h
index 7f341ce73..13fe48540 100644
--- a/src/database/uciengine.h
+++ b/src/database/uciengine.h
@@ -12,7 +12,8 @@
 #define __UCIENGINE_H__
 
 #include <QString>
-#include <QTextStream>
+
+class QTextStream;
 
 #include "engine.h"
 
diff --git a/src/database/wbengine.h b/src/database/wbengine.h
index adc82aa2d..ce42cdb5c 100644
--- a/src/database/wbengine.h
+++ b/src/database/wbengine.h
@@ -11,9 +11,9 @@
 #ifndef __WBENGINE_H__
 #define __WBENGINE_H__
 
-#include <QEvent>
 #include <QString>
-#include <QTextStream>
+
+class QTextStream;
 
 #include "engine.h"
 
diff --git a/src/gui/analysiswidget.cpp b/src/gui/analysiswidget.cpp
index c607c1657..9a636d576 100644
--- a/src/gui/analysiswidget.cpp
+++ b/src/gui/analysiswidget.cpp
@@ -13,6 +13,7 @@
 #include "analysiswidget.h"
 #include "enginelist.h"
 #include "messagedialog.h"
+#include "tablebase.h"
 
 AnalysisWidget::AnalysisWidget()
     : m_engine(0),
diff --git a/src/gui/analysiswidget.h b/src/gui/analysiswidget.h
index 15b7598de..1e49ea5fa 100644
--- a/src/gui/analysiswidget.h
+++ b/src/gui/analysiswidget.h
@@ -12,7 +12,6 @@
 
 #include "engine.h"
 #include "ui_analysiswidget.h"
-#include "tablebase.h"
 #include <QtGui>
 
 /** @ingroup GUI
@@ -21,6 +20,7 @@
 
 class Analysis;
 class Board;
+class Tablebase;
 
 class AnalysisWidget : public QWidget
 {
diff --git a/src/gui/databaselist.h b/src/gui/databaselist.h
index e8f091b5f..5a3bf9dfc 100644
--- a/src/gui/databaselist.h
+++ b/src/gui/databaselist.h
@@ -6,7 +6,6 @@
 #define DATABASELIST_H
 
 #include "tableview.h"
-#include "game.h"
 
 class QSortFilterProxyModel;
 class DatabaseListModel;
diff --git a/src/gui/mainwindow.h b/src/gui/mainwindow.h
index d361b5800..1655521f1 100644
--- a/src/gui/mainwindow.h
+++ b/src/gui/mainwindow.h
@@ -12,8 +12,6 @@
 
 #include "common.h"
 #include "historylist.h"
-#include "kbaction.h"
-#include "move.h"
 #include "output.h"
 
 #include <QtGui>
diff --git a/src/gui/shellhelper.h b/src/gui/shellhelper.h
index 70751fe5d..ccb5788a1 100644
--- a/src/gui/shellhelper.h
+++ b/src/gui/shellhelper.h
@@ -2,11 +2,11 @@
 *   Copyright (C) 2014 by Jens Nissen jens-chessx@gmx.net                   *
 ****************************************************************************/
 
-#include <QtCore>
-
 #ifndef SHELLHELPER_H
 #define SHELLHELPER_H
 
+#include <QString>
+
 class ShellHelper
 {
 public:
diff --git a/src/gui/tableview.h b/src/gui/tableview.h
index 6cd47368b..6d5728f84 100644
--- a/src/gui/tableview.h
+++ b/src/gui/tableview.h
@@ -9,7 +9,6 @@
 
 #include <QtCore>
 #include <QTableView>
-#include <QTreeView>
 
 /**
 	The TableView class is a specialized version of QTableView with automatic