diff --git a/unix/common/unixcommon.h b/unix/common/unixcommon.h
new file mode 100644
index 0000000..66fe84c
--- /dev/null
+++ b/unix/common/unixcommon.h
@@ -0,0 +1,40 @@
+/* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
+ * Copyright 2009-2015 Pierre Ossman for Cendio AB
+ * 
+ * This 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 software 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 software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+#ifndef UNIXCOMMON_H
+#define UNIXCOMMON_H
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <map>
+
+#include <rfb/ScreenSet.h>
+
+typedef std::map<unsigned int, rdr::U32> OutputIdMap;
+
+rfb::ScreenSet computeScreenLayout(int screenIndex, OutputIdMap *outputIdMap);
+
+unsigned int setScreenLayout(int screenIndex,
+                             int fb_width, int fb_height, const rfb::ScreenSet& layout,
+                             OutputIdMap *outputIdMap);
+
+
+#endif /* UNIXCOMMON_H */