diff --git a/libs/pbd/ffs.cc b/libs/pbd/ffs.cc
new file mode 100644
index 0000000000..8f7ecdb502
--- /dev/null
+++ b/libs/pbd/ffs.cc
@@ -0,0 +1,35 @@
+/*
+    Copyright (C) 2013 Tim Mayberry 
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include "pbd/ffs.h"
+
+#include <strings.h>
+
+namespace PBD {
+int
+ffs (int x)
+{
+#if defined(WIN32) && defined(__GNUC__)
+	return __builtin_ffs(x);
+#else
+	return ffs(x);
+#endif
+}
+
+}
diff --git a/libs/pbd/pbd/ffs.h b/libs/pbd/pbd/ffs.h
new file mode 100644
index 0000000000..3a2eadfae7
--- /dev/null
+++ b/libs/pbd/pbd/ffs.h
@@ -0,0 +1,27 @@
+/*
+    Copyright (C) 2013 Tim Mayberry 
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __libpbd_ffs_h__
+#define __libpbd_ffs_h__
+
+namespace PBD {
+	int ffs(int x);
+} 
+
+#endif  /* __libpbd_ffs_h__ */
diff --git a/libs/pbd/wscript b/libs/pbd/wscript
index 91d9b2c50b..e26b96ca11 100644
--- a/libs/pbd/wscript
+++ b/libs/pbd/wscript
@@ -45,6 +45,7 @@ libpbd_sources = [
     'enums.cc',
     'epa.cc',
     'error.cc',
+    'ffs.cc',
     'file_manager.cc',
     'file_utils.cc',
     'fpu.cc',