diff --git a/hypopg_import.c b/hypopg_import.c
index 1185aef..4292b8a 100644
--- a/hypopg_import.c
+++ b/hypopg_import.c
@@ -62,7 +62,7 @@ build_index_tlist(PlannerInfo *root, IndexOptInfo *index,
 		if (indexkey != 0)
 		{
 			/* simple column */
-			Form_pg_attribute att_tup;
+			const FormData_pg_attribute *att_tup;
 
 			if (indexkey < 0)
 				att_tup = SystemAttributeDefinition(indexkey,