diff --git a/src/backend/access/nbtree/nbtdedup.c b/src/backend/access/nbtree/nbtdedup.c
index cb53ce45782..c4a272714aa 100644
--- a/src/backend/access/nbtree/nbtdedup.c
+++ b/src/backend/access/nbtree/nbtdedup.c
@@ -65,7 +65,7 @@ _bt_dedup_one_page(Relation rel, Buffer buf, Relation heapRel,
 	OffsetNumber deletable[MaxIndexTuplesPerPage];
 	BTDedupState state;
 	int			ndeletable = 0;
-	Size		pagesaving = 0;
+	Size		pagesaving PG_USED_FOR_ASSERTS_ONLY = 0;
 	bool		singlevalstrat = false;
 	int			nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);