diff --git a/sql/sql_select.h b/sql/sql_select.h
index 6542bb02392..805026967a0 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -623,11 +623,6 @@ typedef struct st_join_table {
     It is only used to prune searches in best_extension_by_limited_search()
   */
   table_map     key_dependent;
-   /*
-    Tables that have expression in their attached condition clause that depends
-    on this table.
-  */
-  table_map     related_tables;
 
   /*
     Bitmap of TAB_INFO_* bits that encodes special line for EXPLAIN 'Extra'