diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 1dfe343b79c..cc4bf3b5009 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1514,7 +1514,7 @@ pg_newlocale_from_collation(Oid collid)
 		/* We haven't computed this yet in this session, so do it */
 		HeapTuple	tp;
 		Form_pg_collation collform;
-		const char *collcollate;
+		const char *collcollate pg_attribute_unused();
 		const char *collctype pg_attribute_unused();
 		struct pg_locale_struct result;
 		pg_locale_t resultp;