Roman Catechism 16.116

Chapter 16 — Part II: The Sacraments — Baptism

Section 116. Baptism Not To Be Repeated — Since on account of the nature and efficacy of this character it has been defined by the Church that this Sacrament is on no account to be reiterated, pastors should frequently and diligently admonish the faithful on this subject, lest at any time they may be led into error.