diff --git a/zscript-doc.md b/zscript-doc.md
index c2f3064..edcc0eb 100644
--- a/zscript-doc.md
+++ b/zscript-doc.md
@@ -1248,6 +1248,7 @@ struct Vector2
 struct Vector3
 {
    double x, y, z;
+   Vector2 xy;
 
    double Length() const;
    Vector3 Unit() const;