diff --git a/src/rendermode-lighting.c b/src/rendermode-lighting.c
index e836fcf..d0d4c64 100644
--- a/src/rendermode-lighting.c
+++ b/src/rendermode-lighting.c
@@ -110,7 +110,7 @@ get_lighting_coefficient(RenderModeLighting *self, RenderState *state,
         }
 
         if (skylevel) { /* if we have a good skylevel use it, if not iterate */
-            return calculate_darkness(skylevel, blocklevel);
+            return self->calculate_darkness(skylevel, blocklevel);
         } else {
 
             /* iterate through all surrounding blocks to take an average */