diff --git a/src/ray.rs b/src/ray.rs
index 6490e20..be43aaa 100644
--- a/src/ray.rs
+++ b/src/ray.rs
@@ -13,6 +13,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::marker::PhantomData;
 use num::BaseNum;
 use point::{Point, Point2, Point3};
 use vector::{Vector, Vector2, Vector3};
@@ -20,17 +21,21 @@ use vector::{Vector, Vector2, Vector3};
 /// A generic ray starting at `origin` and extending infinitely in
 /// `direction`.
 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable)]
-pub struct Ray<P,V> {
+pub struct Ray<S, P, V> {
     pub origin: P,
     pub direction: V,
+    phantom_s: PhantomData<S>
 }
 
-#[old_impl_check]
-impl<S: BaseNum, V: Vector<S>, P: Point<S, V>> Ray<P, V> {
-    pub fn new(origin: P, direction: V) -> Ray<P,V> {
-        Ray { origin: origin, direction: direction }
+impl<S: BaseNum, V: Vector<S>, P: Point<S, V>> Ray<S, P, V> {
+    pub fn new(origin: P, direction: V) -> Ray<S, P, V> {
+        Ray {
+        	origin: origin,
+        	direction: direction,
+        	phantom_s: PhantomData
+        }
     }
 }
 
-pub type Ray2<S> = Ray<Point2<S>, Vector2<S>>;
-pub type Ray3<S> = Ray<Point3<S>, Vector3<S>>;
+pub type Ray2<S> = Ray<S, Point2<S>, Vector2<S>>;
+pub type Ray3<S> = Ray<S, Point3<S>, Vector3<S>>;
diff --git a/src/rotation.rs b/src/rotation.rs
index 8e92d31..d2335dc 100644
--- a/src/rotation.rs
+++ b/src/rotation.rs
@@ -49,7 +49,7 @@ pub trait Rotation<S: BaseNum, V: Vector<S>, P: Point<S, V>>: PartialEq + Approx
 
     /// Rotate a ray using this rotation.
     #[inline]
-    fn rotate_ray(&self, ray: &Ray<P, V>) -> Ray<P,V> {
+    fn rotate_ray(&self, ray: &Ray<S, P, V>) -> Ray<S, P,V> {
         Ray::new(ray.origin.clone(), self.rotate_vector(&ray.direction))
     }
 
diff --git a/src/transform.rs b/src/transform.rs
index 936b3af..0382839 100644
--- a/src/transform.rs
+++ b/src/transform.rs
@@ -44,7 +44,7 @@ pub trait Transform<S: BaseNum, V: Vector<S>, P: Point<S, V>>: Sized + PhantomFn
 
     /// Transform a ray using this transform.
     #[inline]
-    fn transform_ray(&self, ray: &Ray<P,V>) -> Ray<P, V> {
+    fn transform_ray(&self, ray: &Ray<S, P,V>) -> Ray<S, P, V> {
         Ray::new(self.transform_point(&ray.origin), self.transform_vector(&ray.direction))
     }