diff --git a/src/cairo-path-stroke-polygon.c b/src/cairo-path-stroke-polygon.c
index 2c8fe5e..42b1218 100644
--- a/src/cairo-path-stroke-polygon.c
+++ b/src/cairo-path-stroke-polygon.c
@@ -190,6 +190,7 @@ add_fan (struct stroker *stroker,
 	_cairo_pen_find_active_ccw_vertices (pen,
 					     in_vector, out_vector,
 					     &start, &stop);
+	start--;
 	while (start != stop) {
 	    cairo_point_t p = *midpt;
 	    translate_point (&p, &pen->vertices[start].point);