diff --git a/util.go b/util.go
index a530fcb..8c34809 100644
--- a/util.go
+++ b/util.go
@@ -54,8 +54,9 @@ func SavePNG(path string, im image.Image) error {
 }
 
 func imageToRGBA(src image.Image) *image.RGBA {
-	dst := image.NewRGBA(src.Bounds())
-	draw.Draw(dst, dst.Rect, src, image.ZP, draw.Src)
+	bounds := src.Bounds()
+	dst := image.NewRGBA(bounds)
+	draw.Draw(dst, bounds, src, bounds.Min, draw.Src)
 	return dst
 }