diff --git a/internal/scoreonescriptspan.h b/internal/scoreonescriptspan.h
index b6f9b52..8fe717b 100644
--- a/internal/scoreonescriptspan.h
+++ b/internal/scoreonescriptspan.h
@@ -103,7 +103,8 @@ typedef struct {
   const CLD2TableSummary* deltabi_obj;
   const CLD2TableSummary* distinctbi_obj;
 
-  const CLD2TableSummary* quadgram_obj;
+  const CLD2TableSummary* quadgram_obj;         // Primary quadgram lookup table
+  const CLD2TableSummary* quadgram_obj2;        // Secondary  "
   const CLD2TableSummary* deltaocta_obj;
   const CLD2TableSummary* distinctocta_obj;