Every petition under this Act, except a petition under Section 8-1 or Section 8-2, shall be under oath or affirmation. If a statement is known to petitioner only upon information and belief, or is unknown to him, the petition shall so state. Whenever any instrument is required to be verified or under oath, a statement that is made under the penalties of perjury has the same effect as if the instrument were verified or made under oath. A fraudulent statement so made is perjury, as defined in Section 32-2 of the Criminal Code of 2012.
755 ILCS 5/1-5