diff --git a/interface.go b/interface.go
index e0adceccc02aacdf1dc07cc7c7f1e39b824de67c..45300071b2d8c510db1852451a9da66a1ecdbbf4 100644
--- a/interface.go
+++ b/interface.go
@@ -129,5 +129,6 @@ type TargetPicture interface {
 //
 // Positions outside the Picture's Bounds must return opaque white (NRGBA{R: 1, G: 1, B:1, A: 1}).
 type PictureColor interface {
+	Picture
 	Color(at Vec) NRGBA
 }