You must be very careful in choosing the witnesses to your will. A normal will,(in other words, not a handwritten holographic will which is an entirely different topic,) requires a will to be signed by the person making the will and in front of two witnesses who must also sign their name.
However, no beneficiary or their spouse may be a witness. If they are, to paraphrase, Section 12 of the Succession Law Reform Act “where a will is witnessed by a person to whom or whose spouse is a beneficiary, the inheritance is void as it concerns the witness, their spouse or any person claiming under either of them”. So, be careful, it is important that the witnesses are completely unrelated and also in no way a beneficiary under the will.