diff --git a/Lighting.java b/Lighting.java
index 3bc3b9c..5c3c644 100644
--- a/Lighting.java
+++ b/Lighting.java
@@ -82,10 +82,10 @@ public class Lighting {
                         double Id = light.params[3];
 
                         /* diffuse contribution */
-                        double I_diff = Id * kd * Math.cos(normal.dot(l));
+                        double I_diff = Id * kd * normal.dot(l) / normal.norm() / l.norm();
 
                         /* specular contribution */
-                        double I_spec = Id * ks * Math.pow(Math.cos(h.dot(normal)), s);
+                        double I_spec = Id * ks * Math.pow(h.dot(normal) / h.norm() / normal.norm(), s);
 
                         I += I_diff + I_spec;
                     } catch (InstantiationException ex) {