diff --git a/Lighting.java b/Lighting.java
index 02948c8..8edde13 100644
--- a/Lighting.java
+++ b/Lighting.java
@@ -85,7 +85,7 @@ public class Lighting {
                         double I_diff = Id * kd * Math.cos(normal.dot(l));
 
                         /* specular contribution */
-                        double I_spec = Id * ks * Math.cos(h.dot(normal));
+                        double I_spec = Id * ks * Math.pow(Math.cos(h.dot(normal)), 2);
 
                         I += I_diff + I_spec;
                     } catch (InstantiationException ex) {