diff --git a/svg.h b/svg.h
index 2060d2c..8e959f0 100644
--- a/svg.h
+++ b/svg.h
@@ -1,7 +1,9 @@
 #ifndef SVG_H_INCLUDED
 #define SVG_H_INCLUDED
 
+#include <vector>
 void
-svg_begin(double width, double height)
+show_histogram_svg(const std::vector<size_t>& bins, size_t number_count);
+
 
 #endif // SVG_H_INCLUDED