diff --git a/rtchallenge/src/lights.rs b/rtchallenge/src/lights.rs
index 3a1d942..fe02f0a 100644
--- a/rtchallenge/src/lights.rs
+++ b/rtchallenge/src/lights.rs
@@ -1,6 +1,6 @@
 use crate::tuples::{Color, Tuple};
 
-#[derive(Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct PointLight {
     pub position: Tuple,
     pub intensity: Color,
diff --git a/rtchallenge/src/world.rs b/rtchallenge/src/world.rs
index 83bc3e5..13a875e 100644
--- a/rtchallenge/src/world.rs
+++ b/rtchallenge/src/world.rs
@@ -20,7 +20,7 @@ use crate::{
 /// assert_eq!(w.light, None);
 /// ```
 
-#[derive(Debug, Default)]
+#[derive(Clone, Debug, Default)]
 pub struct World {
     // TODO(wathiede): make this a list of abstract Light traits.
     pub light: Option<PointLight>,