1 files changed, 3 insertions, 2 deletions
diff --git a/src/hittable.rs b/src/hittable.rs
index 1c61872..dcc5006 100644
--- a/src/hittable.rs
+++ b/src/hittable.rs
@@ -7,11 +7,12 @@ pub struct Hit<'a> {
     pub p: Vector3<f64>,
     pub normal: Vector3<f64>,
     pub front_face: bool,
-    pub material: &'a (dyn Material)
+    pub material: &'a (dyn Material + std::marker::Sync)
 }
 
 impl<'a> Hit<'a> {
-    pub fn new(ray: &Ray, t: f64, out_normal: Vector3<f64>, material: &'a(dyn Material)) -> Hit<'a> {
+    pub fn new(ray: &Ray, t: f64, out_normal: Vector3<f64>, material: &'a(dyn Material + std::marker::Sync))
+               -> Hit<'a> {
         let front_face = dot(ray.dir, out_normal) < 0.0;
         let normal = if front_face { out_normal } else { -out_normal };
         let p = ray.at(t);