diff --git a/graph.h b/graph.h
index 872e60e..39dd2b0 100644
--- a/graph.h
+++ b/graph.h
@@ -6,6 +6,7 @@
 #define INVISIBLE_COLOR (-1.0)
 
 struct graph *graph_new(unsigned int xdim, unsigned int ydim, const char *font);
+void graph_set_size(struct graph *g, unsigned int xdim, unsigned int ydim);
 void bar_graph_draw(struct graph *g, cairo_t *cr);
 void line_graph_draw(struct graph *g, cairo_t *cr);
 void line_graph_set_data_count_limit(struct graph *g, int per_label_limit);