diff --git a/src/world.rs b/src/world.rs
index 2df88dd..bdc0768 100644
--- a/src/world.rs
+++ b/src/world.rs
@@ -42,12 +42,12 @@ pub fn setup(
     // Add spheres
     let sphere_radius = 50.0;
     let sphere_handle = meshes.add(Sphere::new(sphere_radius));
-    let gray = materials.add(StandardMaterial {
+    let gray_handle = materials.add(StandardMaterial {
         base_color: Color::GRAY,
         perceptual_roughness: 1.0,
         ..default()
     });
-    let brown = materials.add(StandardMaterial {
+    let brown_handle = materials.add(StandardMaterial {
         base_color: Color::Rgba { alpha: 1.0, red: 0.8, green: 0.5, blue: 0.1 },
         perceptual_roughness: 1.0,
         ..default()
@@ -55,7 +55,7 @@ pub fn setup(
 
     commands.spawn(PbrBundle {
         mesh: sphere_handle.clone(),
-        material: gray.clone(),
+        material: gray_handle.clone(),
         transform: Transform::from_xyz(
             0.0,
             0.0,
@@ -68,7 +68,7 @@ pub fn setup(
     let sphere_handle = meshes.add(Sphere::new(sphere_radius));
     commands.spawn(PbrBundle {
         mesh: sphere_handle.clone(),
-        material: brown.clone(),
+        material: brown_handle.clone(),
         transform: Transform::from_xyz(
             300.0,
             40.0,