diff --git a/externals/build/include/g_canvas.h b/externals/build/include/g_canvas.h
index 6dde2060771e6a8a1a3259a9f5a8072c72b585e5..d847b51b0e1a8baeaee1014c787cce4720b6828b 100644
--- a/externals/build/include/g_canvas.h
+++ b/externals/build/include/g_canvas.h
@@ -770,6 +770,7 @@ void *qt_thread_main (void *);
 /* ---------- other things added by Mathieu (aug.2014) ----------------- */
 
 void canvas_raise_all_cords (t_canvas *x);
+void canvas_getscroll (t_canvas *x);
 
 /* --------------------------------------------------------------------- */