diff --git a/pokerth_game.pro b/pokerth_game.pro
index ccae778a..bad7b3b5 100644
--- a/pokerth_game.pro
+++ b/pokerth_game.pro
@@ -14,6 +14,8 @@ OBJECTS_DIR = obj
 DEFINES += ENABLE_IPV6
 DEFINES += PREFIX=\"$${PREFIX}\"
 TARGET = pokerth
+#PRECOMPILED_HEADER = src/pch_game.h
+
 RESOURCES = src/gui/qt/resources/pokerth.qrc
 INCLUDEPATH += . \
     src \
diff --git a/pokerth_lib.pro b/pokerth_lib.pro
index 3d707d5d..dc2ca0b9 100644
--- a/pokerth_lib.pro
+++ b/pokerth_lib.pro
@@ -12,6 +12,7 @@ MOC_DIR = mocs
 OBJECTS_DIR = obj
 DEFINES += ENABLE_IPV6
 QT -= core gui
+#PRECOMPILED_HEADER = src/pch_lib.h
 
 INCLUDEPATH += . \
 		src \
diff --git a/pokerth_server.pro b/pokerth_server.pro
index eb4fbfd1..bf0d12d6 100644
--- a/pokerth_server.pro
+++ b/pokerth_server.pro
@@ -18,6 +18,7 @@ DEFINES += POKERTH_DEDICATED_SERVER
 DEFINES += ENABLE_IPV6
 DEFINES += PREFIX=\"$${PREFIX}\"
 QT -= core gui
+#PRECOMPILED_HEADER = src/pch_lib.h
 
 INCLUDEPATH += . \
 		src \
diff --git a/src/core/avatarmanager.h b/src/core/avatarmanager.h
index 8ba7e8d6..36934767 100644
--- a/src/core/avatarmanager.h
+++ b/src/core/avatarmanager.h
@@ -21,15 +21,13 @@
 #ifndef _AVATARMANAGER_H_
 #define _AVATARMANAGER_H_
 
-#include <net/netpacket.h>
-#include <playerdata.h>
-#include <core/crypthelper.h>
-#include <ctime>
+#include <boost/thread.hpp>
+#include <boost/shared_ptr.hpp>
+
 #include <map>
 #include <list>
 
-#include <boost/thread.hpp>
-#include <boost/shared_ptr.hpp>
+#include <net/netpacket.h>
 
 #define MIN_AVATAR_FILE_SIZE	32
 #define MAX_AVATAR_FILE_SIZE	30720
diff --git a/src/engine/berointerface.h b/src/engine/berointerface.h
index 30d4de3c..c1b88f5a 100644
--- a/src/engine/berointerface.h
+++ b/src/engine/berointerface.h
@@ -23,7 +23,7 @@
 #include <boost/shared_ptr.hpp>
 #include <list>
 
-#include "game_defs.h"
+#include <game_defs.h>
 
 class PlayerInterface;
 
diff --git a/src/engine/boardinterface.h b/src/engine/boardinterface.h
index 01511d22..ab1cc612 100644
--- a/src/engine/boardinterface.h
+++ b/src/engine/boardinterface.h
@@ -20,9 +20,9 @@
 #ifndef BOARDINTERFACE_H
 #define BOARDINTERFACE_H
 
+#include <boost/shared_ptr.hpp>
 #include <vector>
 #include <list>
-#include <boost/shared_ptr.hpp>
 
 class PlayerInterface;
 class HandInterface;
diff --git a/src/engine/enginefactory.h b/src/engine/enginefactory.h
index ec055c18..3b844d84 100644
--- a/src/engine/enginefactory.h
+++ b/src/engine/enginefactory.h
@@ -25,8 +25,6 @@
 #include "playerinterface.h"
 #include "berointerface.h"
 
-#include <boost/shared_ptr.hpp>
-
 
 class EngineFactory{
 public:
diff --git a/src/engine/handinterface.h b/src/engine/handinterface.h
index d1f41a4c..9f850881 100644
--- a/src/engine/handinterface.h
+++ b/src/engine/handinterface.h
@@ -20,10 +20,6 @@
 #ifndef HANDINTERFACE_H
 #define HANDINTERFACE_H
 
-#include <vector>
-
-#include <boost/shared_ptr.hpp>
-
 #include "guiinterface.h"
 #include "boardinterface.h"
 #include "playerinterface.h"
diff --git a/src/engine/playerinterface.h b/src/engine/playerinterface.h
index 87cb9019..77161e24 100644
--- a/src/engine/playerinterface.h
+++ b/src/engine/playerinterface.h
@@ -23,8 +23,6 @@
 #include "handinterface.h"
 #include <playerdata.h>
 
-#include <boost/shared_ptr.hpp>
-
 class SessionData;
 
 class PlayerInterface{
diff --git a/src/game.h b/src/game.h
index ddcb51e0..1fe7634c 100755
--- a/src/game.h
+++ b/src/game.h
@@ -20,13 +20,10 @@
 #ifndef GAME_H
 #define GAME_H
 
-#include "game_defs.h"
+#include <boost/shared_ptr.hpp>
 #include "gamedata.h"
 #include "playerdata.h"
-#include "configfile.h"
 
-#include <string>
-#include <boost/shared_ptr.hpp>
 #include <third_party/boost/timers.hpp>
 
 class GuiInterface;
diff --git a/src/gamedata.h b/src/gamedata.h
index 7f28ba65..fd22dad0 100644
--- a/src/gamedata.h
+++ b/src/gamedata.h
@@ -21,11 +21,14 @@
 #ifndef _GAMEDATA_H_
 #define _GAMEDATA_H_
 
-#include <playerdata.h>
+#include <list>
+#include <string>
 #include <third_party/boost/timers.hpp>
 
 #define SERVER_COMPUTER_PLAYER_NAME			"Computer"
 
+typedef std::list<unsigned> PlayerIdList;
+
 enum GameMode
 {
 	GAME_MODE_CREATED = 1,
diff --git a/src/net/clientcallback.h b/src/net/clientcallback.h
index 262db9d2..dce1d8ff 100644
--- a/src/net/clientcallback.h
+++ b/src/net/clientcallback.h
@@ -21,8 +21,9 @@
 #ifndef _CLIENTCALLBACK_H_
 #define _CLIENTCALLBACK_H_
 
-#include <string>
 #include <boost/shared_ptr.hpp>
+#include <string>
+
 #include <playerdata.h>
 #include <game_defs.h>
 #include <gamedata.h>
diff --git a/src/net/clientcontext.h b/src/net/clientcontext.h
index 0e338841..61158b7b 100644
--- a/src/net/clientcontext.h
+++ b/src/net/clientcontext.h
@@ -21,10 +21,11 @@
 #ifndef _CLIENTCONTEXT_H_
 #define _CLIENTCONTEXT_H_
 
+#include <boost/shared_ptr.hpp>
+
 #include <net/netcontext.h>
 #include <net/receivebuffer.h>
 #include <net/sessiondata.h>
-#include <boost/shared_ptr.hpp>
 
 
 class ClientContext : public NetContext
diff --git a/src/net/clientstate.h b/src/net/clientstate.h
index 592b12e4..ca536a5f 100644
--- a/src/net/clientstate.h
+++ b/src/net/clientstate.h
@@ -21,10 +21,11 @@
 #ifndef _CLIENTSTATE_H_
 #define _CLIENTSTATE_H_
 
-#include <net/socket_helper.h> // needed for correct order of header files.
+#include <third_party/boost/timers.hpp>
 #include <string>
 #include <memory>
-#include <third_party/boost/timers.hpp>
+
+#include <net/socket_helper.h> // needed for correct order of header files.
 
 #define CLIENT_INITIAL_STATE ClientStateInit
 
diff --git a/src/net/clientthread.h b/src/net/clientthread.h
index 6b74eeac..af48ea9e 100644
--- a/src/net/clientthread.h
+++ b/src/net/clientthread.h
@@ -21,14 +21,15 @@
 #ifndef _CLIENTTHREAD_H_
 #define _CLIENTTHREAD_H_
 
+#include <boost/shared_ptr.hpp>
+#include <string>
+
 #include <core/thread.h>
 #include <net/senderinterface.h>
 #include <guiinterface.h>
 #include <serverdata.h>
 #include <playerdata.h>
 #include <gamedata.h>
-#include <string>
-#include <boost/shared_ptr.hpp>
 
 class ClientContext;
 class ClientState;
diff --git a/src/net/downloaderthread.h b/src/net/downloaderthread.h
index c1fa2e51..10b031c1 100644
--- a/src/net/downloaderthread.h
+++ b/src/net/downloaderthread.h
@@ -21,11 +21,11 @@
 #ifndef _DOWNLOADERTHREAD_H_
 #define _DOWNLOADERTHREAD_H_
 
-#include <core/thread.h>
-
+#include <boost/shared_ptr.hpp>
 #include <queue>
 #include <vector>
-#include <boost/shared_ptr.hpp>
+
+#include <core/thread.h>
 
 #define DOWNLOADER_THREAD_TERMINATE_TIMEOUT		THREAD_WAIT_INFINITE
 class DownloadHelper;
diff --git a/src/net/ircthread.h b/src/net/ircthread.h
index 4951e326..2d76b6bd 100644
--- a/src/net/ircthread.h
+++ b/src/net/ircthread.h
@@ -21,11 +21,12 @@
 #ifndef _IRCTHREAD_H_
 #define _IRCTHREAD_H_
 
-#include <net/irccallback.h>
-#include <core/thread.h>
 #include <third_party/boost/timers.hpp>
 #include <string>
 
+#include <net/irccallback.h>
+#include <core/thread.h>
+
 struct IrcContext;
 
 class IrcThread : public Thread
diff --git a/src/net/netpacket.h b/src/net/netpacket.h
index d8f4d9f8..24b248f0 100644
--- a/src/net/netpacket.h
+++ b/src/net/netpacket.h
@@ -21,15 +21,15 @@
 #ifndef _NETPACKET_H_
 #define _NETPACKET_H_
 
+#include <vector>
+#include <list>
+
 #include <net/socket_helper.h>
 #include <playerdata.h>
 #include <game_defs.h>
 #include <gamedata.h>
 #include <core/crypthelper.h>
 
-#include <vector>
-#include <list>
-
 #define NET_VERSION_MAJOR			5
 #define NET_VERSION_MINOR			2
 
diff --git a/src/net/receivebuffer.h b/src/net/receivebuffer.h
index 866556ee..7f635a3b 100644
--- a/src/net/receivebuffer.h
+++ b/src/net/receivebuffer.h
@@ -22,7 +22,6 @@
 #define _RECEIVEBUFFER_H_
 
 #include <net/netpacket.h>
-#include <list>
 
 // MUST be larger than MAX_PACKET_SIZE
 #define RECV_BUF_SIZE		2 * MAX_PACKET_SIZE
diff --git a/src/net/receiverhelper.h b/src/net/receiverhelper.h
index 1aa70bfc..927e535c 100644
--- a/src/net/receiverhelper.h
+++ b/src/net/receiverhelper.h
@@ -21,12 +21,13 @@
 #ifndef _RECEIVERHELPER_H_
 #define _RECEIVERHELPER_H_
 
+#include <boost/shared_ptr.hpp>
+#include <deque>
+
 #include <net/socket_helper.h>
 #include <net/netpacket.h>
 #include <net/receivebuffer.h>
 
-#include <deque>
-#include <boost/shared_ptr.hpp>
 
 class ReceiverHelper
 {
diff --git a/src/net/resolverthread.h b/src/net/resolverthread.h
index 3186b55a..61997480 100644
--- a/src/net/resolverthread.h
+++ b/src/net/resolverthread.h
@@ -21,9 +21,9 @@
 #ifndef _RESOLVERTHREAD_H_
 #define _RESOLVERTHREAD_H_
 
-#include <core/thread.h>
 #include <string>
-#include <boost/shared_ptr.hpp>
+
+#include <core/thread.h>
 
 class ClientContext;
 
diff --git a/src/net/senderinterface.h b/src/net/senderinterface.h
index 01d94e10..9773fa5c 100644
--- a/src/net/senderinterface.h
+++ b/src/net/senderinterface.h
@@ -23,7 +23,6 @@
 
 #include <net/sessiondata.h>
 #include <net/netpacket.h>
-#include <boost/shared_ptr.hpp>
 
 class SenderInterface
 {
diff --git a/src/net/senderthread.h b/src/net/senderthread.h
index 557863b4..db79af27 100644
--- a/src/net/senderthread.h
+++ b/src/net/senderthread.h
@@ -26,9 +26,6 @@
 #include <net/netpacket.h>
 #include <net/sendercallback.h>
 
-#include <list>
-#include <boost/shared_ptr.hpp>
-
 class SessionData;
 class SendDataManager;
 #define SENDER_THREAD_TERMINATE_TIMEOUT		THREAD_WAIT_INFINITE
diff --git a/src/net/serveracceptthread.h b/src/net/serveracceptthread.h
index 003c953e..3f94f42f 100644
--- a/src/net/serveracceptthread.h
+++ b/src/net/serveracceptthread.h
@@ -22,9 +22,10 @@
 #define _SERVERACCEPTTHREAD_H_
 
 #include <boost/asio.hpp>
+#include <string>
+
 #include <game_defs.h>
 #include <gui/guiinterface.h>
-#include <string>
 
 class ServerLobbyThread;
 
diff --git a/src/net/servergamestate.h b/src/net/servergamestate.h
index 8576897f..84bff815 100644
--- a/src/net/servergamestate.h
+++ b/src/net/servergamestate.h
@@ -23,7 +23,6 @@
 
 #include <net/servergamethread.h>
 #include <playerdata.h>
-#include <third_party/boost/timers.hpp>
 
 
 #ifdef _MSC_VER
diff --git a/src/net/servergamethread.h b/src/net/servergamethread.h
index 2978bcb7..78e33c25 100644
--- a/src/net/servergamethread.h
+++ b/src/net/servergamethread.h
@@ -21,12 +21,13 @@
 #ifndef _SERVERGAMETHREAD_H_
 #define _SERVERGAMETHREAD_H_
 
+#include <third_party/boost/timers.hpp>
+#include <deque>
+
 #include <net/sessionmanager.h>
 #include <gui/guiinterface.h>
 #include <gamedata.h>
-#include <third_party/boost/timers.hpp>
 
-#include <deque>
 
 #define GAME_THREAD_TERMINATE_TIMEOUT	THREAD_WAIT_INFINITE
 
diff --git a/src/net/serverlobbythread.h b/src/net/serverlobbythread.h
index f23d7140..6e51d01f 100644
--- a/src/net/serverlobbythread.h
+++ b/src/net/serverlobbythread.h
@@ -22,16 +22,15 @@
 #define _SERVERRECVTHREAD_H_
 
 #include <boost/asio.hpp>
+#include <deque>
+#include <boost/regex.hpp>
+
 #include <core/timermanager.h>
 #include <net/sessionmanager.h>
 #include <net/netpacket.h>
 #include <gui/guiinterface.h>
 #include <gamedata.h>
 
-#include <deque>
-#include <list>
-#include <boost/regex.hpp>
-#include <third_party/boost/timers.hpp>
 
 #define NET_LOBBY_THREAD_TERMINATE_TIMEOUT_MSEC		20000
 #define NET_ADMIN_IRC_TERMINATE_TIMEOUT_MSEC		4000
diff --git a/src/net/servermanager.h b/src/net/servermanager.h
index aeb5f86c..0b986e03 100644
--- a/src/net/servermanager.h
+++ b/src/net/servermanager.h
@@ -22,13 +22,13 @@
 #define _SERVERMANAGER_H_
 
 #include <boost/asio.hpp>
-#include <game_defs.h>
-
-#include <gui/guiinterface.h>
 #include <third_party/boost/timers.hpp>
 #include <string>
 #include <list>
 
+#include <game_defs.h>
+#include <gui/guiinterface.h>
+
 class ServerLobbyThread;
 class ServerAcceptThread;
 class SenderThread;
diff --git a/src/net/sessiondata.h b/src/net/sessiondata.h
index 25f4e66b..ed9a02a8 100644
--- a/src/net/sessiondata.h
+++ b/src/net/sessiondata.h
@@ -24,12 +24,13 @@
 typedef unsigned SessionId;
 
 #include <boost/asio.hpp>
+#include <boost/thread.hpp>
+#include <third_party/boost/timers.hpp>
+#include <string>
+
 #include <net/socket_helper.h>
 #include <net/receivebuffer.h>
 #include <net/sessiondatacallback.h>
-#include <string>
-#include <boost/thread.hpp>
-#include <third_party/boost/timers.hpp>
 
 #define INVALID_SESSION			0
 #define SESSION_ID_INIT			INVALID_SESSION
diff --git a/src/net/sessionmanager.h b/src/net/sessionmanager.h
index a3243a8c..3f85188c 100644
--- a/src/net/sessionmanager.h
+++ b/src/net/sessionmanager.h
@@ -21,14 +21,13 @@
 #ifndef _SESSIONMANAGER_H_
 #define _SESSIONMANAGER_H_
 
+#include <boost/function.hpp>
+#include <map>
+
 #include <net/sessiondata.h>
 #include <playerdata.h>
 #include <core/thread.h>
 
-#include <boost/function.hpp>
-#include <map>
-#include <string>
-
 class SenderInterface;
 class NetPacket;
 
diff --git a/src/net/transferhelper.h b/src/net/transferhelper.h
index b4f20b07..d5d45baf 100644
--- a/src/net/transferhelper.h
+++ b/src/net/transferhelper.h
@@ -21,8 +21,8 @@
 #ifndef _TRANSFERHELPER_H_
 #define _TRANSFERHELPER_H_
 
-#include <string>
 #include <boost/shared_ptr.hpp>
+#include <string>
 
 struct TransferData;
 
diff --git a/src/net/uploaderthread.h b/src/net/uploaderthread.h
index c0808c40..a777eaad 100644
--- a/src/net/uploaderthread.h
+++ b/src/net/uploaderthread.h
@@ -21,10 +21,10 @@
 #ifndef _UPLOADERTHREAD_H_
 #define _UPLOADERTHREAD_H_
 
+#include <boost/shared_ptr.hpp>
+#include <queue>
 #include <core/thread.h>
 
-#include <queue>
-#include <boost/shared_ptr.hpp>
 
 #define UPLOADER_THREAD_TERMINATE_TIMEOUT		THREAD_WAIT_INFINITE
 class UploadHelper;
diff --git a/src/pch_game.h b/src/pch_game.h
new file mode 100644
index 00000000..d4f206ef
--- /dev/null
+++ b/src/pch_game.h
@@ -0,0 +1,26 @@
+/***************************************************************************
+ *   Copyright (C) 2009 by Lothar May                                      *
+ *                                                                         *
+ *   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 of the License, 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.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ ***************************************************************************/
+#include "pch_lib.h"
+
+#if defined __cplusplus
+
+#include <QtGui>
+#include <QtCore>
+
+#endif
diff --git a/src/pch_lib.h b/src/pch_lib.h
new file mode 100644
index 00000000..cf7fe13c
--- /dev/null
+++ b/src/pch_lib.h
@@ -0,0 +1,40 @@
+/***************************************************************************
+ *   Copyright (C) 2009 by Lothar May                                      *
+ *                                                                         *
+ *   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 of the License, 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.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ ***************************************************************************/
+#if defined __cplusplus
+
+/* Note: ASIO needs to be included first! */
+#include <boost/asio.hpp>
+#include <boost/thread.hpp>
+#include <boost/thread/barrier.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/regex.hpp>
+#include <boost/function.hpp>
+#include <third_party/boost/timers.hpp>
+
+#include <string>
+#include <list>
+#include <vector>
+#include <map>
+#include <deque>
+
+#else
+
+#include <string.h>
+
+#endif
diff --git a/src/playerdata.h b/src/playerdata.h
index 75357e77..11a86502 100644
--- a/src/playerdata.h
+++ b/src/playerdata.h
@@ -21,13 +21,13 @@
 #ifndef _PLAYERDATA_H_
 #define _PLAYERDATA_H_
 
-#include <core/crypthelper.h>
+#include <boost/shared_ptr.hpp>
+#include <boost/thread.hpp>
 #include <string>
 #include <list>
 #include <vector>
 #include <map>
-#include <boost/shared_ptr.hpp>
-#include <boost/thread.hpp>
+#include <core/crypthelper.h>
 
 class SessionData;
 
@@ -110,7 +110,6 @@ private:
 	mutable boost::mutex			m_dataMutex;
 };
 
-typedef std::list<unsigned> PlayerIdList;
 typedef std::list<std::pair<unsigned, unsigned> > RemovePlayerList;
 typedef std::list<boost::shared_ptr<PlayerData> > PlayerDataList;
 typedef std::map<unsigned, boost::shared_ptr<PlayerData> > PlayerDataMap;
diff --git a/src/session.h b/src/session.h
index f963889e..e31a7231 100755
--- a/src/session.h
+++ b/src/session.h
@@ -19,12 +19,14 @@
  ***************************************************************************/
 #ifndef STDSESSION_H
 #define STDSESSION_H
+
+#include <boost/shared_ptr.hpp>
+#include <string>
+
 #include "serverdata.h"
 #include "gamedata.h"
 #include "playerdata.h"
 #include "game_defs.h"
-#include <string>
-#include <boost/shared_ptr.hpp>
 #include <core/crypthelper.h>
 
 class GuiInterface;
@@ -117,6 +119,4 @@ private:
 	QtToolsInterface *myQtToolsInterface;
 };
 
-
-
 #endif