diff --git a/overviewer_core/src/primitives/smooth-lighting.c b/overviewer_core/src/primitives/smooth-lighting.c
index 86196be..172b330 100644
--- a/overviewer_core/src/primitives/smooth-lighting.c
+++ b/overviewer_core/src/primitives/smooth-lighting.c
@@ -17,6 +17,7 @@
 
 #include "../overviewer.h"
 #include "../mc_id.h"
+#include "../block_class.h"
 #include "lighting.h"
 #include <math.h>