diff -u gtkguitune-0.7/main.cc gtkguitune-0.7/main.cc
--- gtkguitune-0.7/main.cc
+++ gtkguitune-0.7/main.cc
@@ -19,6 +19,7 @@
 //    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 //
 //
+#include <cstdlib>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>