Unexpected error on package_body_variable%TYPE inside a package routine

SET sql_mode=ORACLE;

DELIMITER $$

CREATE OR REPLACE PACKAGE pkg1 IS

  PROCEDURE p1;

END;

$$

CREATE PACKAGE BODY pkg1 IS

  v0 INT;

  PROCEDURE p1 IS

    v1 v0%TYPE;

  BEGIN

    NULL;

  END;

END;

$$

DELIMITER ;

ERROR 1327 (42000): Undeclared variable: v0