diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index fa96ba07bf4..07d182da796 100644
--- a/src/include/catalog/pg_class.h
+++ b/src/include/catalog/pg_class.h
@@ -231,8 +231,8 @@ MAKE_SYSCACHE(RELNAMENSP, pg_class_relname_nsp_index, 128);
 	 (relkind) == RELKIND_TOASTVALUE || \
 	 (relkind) == RELKIND_MATVIEW)
 
-extern int	errdetail_relkind_not_supported(char relkind);
-
 #endif							/* EXPOSE_TO_CLIENT_CODE */
 
+extern int	errdetail_relkind_not_supported(char relkind);
+
 #endif							/* PG_CLASS_H */