diff --git a/src/frontends/qt4/GuiApplication.cpp b/src/frontends/qt4/GuiApplication.cpp
index aaf7add117..a4a9df859f 100644
--- a/src/frontends/qt4/GuiApplication.cpp
+++ b/src/frontends/qt4/GuiApplication.cpp
@@ -27,6 +27,7 @@
 #include "support/os.h"
 #include "support/Package.h"
 
+#include "BufferList.h"
 #include "BufferView.h"
 #include "Color.h"
 #include "debug.h"
@@ -43,6 +44,7 @@
 #include <QLocale>
 #include <QLibraryInfo>
 #include <QPixmapCache>
+#include <QSessionManager>
 #include <QTextCodec>
 #include <QTimer>
 #include <QTranslator>
@@ -318,6 +320,20 @@ void GuiApplication::unregisterSocketCallback(int fd)
 	socket_callbacks_.erase(fd);
 }
 
+
+void GuiApplication::commitData(QSessionManager & sm)
+{
+	/// The implementation is required to avoid an application exit
+	/// when session state save is triggered by session manager.
+	/// The default implementation sends a close event to all
+	/// visible top level widgets when session managment allows
+	/// interaction.
+	/// We are changing that to write all unsaved buffers...
+	if (sm.allowsInteraction() && !theBufferList().quitWriteAll())
+ 		sm.cancel();
+}
+
+
 ////////////////////////////////////////////////////////////////////////
 // X11 specific stuff goes here...
 #ifdef Q_WS_X11
diff --git a/src/frontends/qt4/GuiApplication.h b/src/frontends/qt4/GuiApplication.h
index ba0b4c2d72..954c48e064 100644
--- a/src/frontends/qt4/GuiApplication.h
+++ b/src/frontends/qt4/GuiApplication.h
@@ -26,6 +26,8 @@
 #include <QApplication>
 #include <QTranslator>
 
+class QSessionManager;
+
 namespace lyx {
 
 class BufferView;
@@ -74,9 +76,10 @@ public:
 	void unregisterSocketCallback(int fd);
 	//@}
 
-	/// Methods inherited from \c Application class
+	/// Methods inherited from \c QApplication class
 	//@{
-	virtual bool notify(QObject * receiver, QEvent * event);
+	bool notify(QObject * receiver, QEvent * event);
+	void commitData(QSessionManager & sm);
 	//@}
 
 	///