diff --git a/3-mid/opengl/assets/shader/lighting-frag.snippet b/3-mid/opengl/assets/shader/lighting-frag.snippet
index 9f7f5bd..ac65146 100644
--- a/3-mid/opengl/assets/shader/lighting-frag.snippet
+++ b/3-mid/opengl/assets/shader/lighting-frag.snippet
@@ -36,7 +36,7 @@ apply_Light (light   Light,
     {
         // Directional light.
         //
-        Surface_to_Light = normalize (-Light.Site.xyz);
+        Surface_to_Light = normalize (Light.Site.xyz);
         Attenuation      = 1.0;                             // No attenuation for directional lights.
     } 
     else