Oracle regexp_like square brackets inside character set

This questions is in regards to Oracle, pl/sql, and the regexp_like function. I am trying to build a character set that will match on all typical special characters. My character set currently looks like: pattern := '[-~`!@#$%^&*\(\)\\{}_+=|''";:,./?]+'; I would like to add the square brackets to this character set, however, whatever I try to add ']' is not working. Here is a simple example that illustrates the problem: select case when regexp_like('w]ord', '[\]]+') then 'true' else 'false' end from dual; This returns false, meaning it did not match the ']' character. Curiously, I can get the '[' character to match because this returns true: select case when regexp_like('w[ord', '[\[]+') then 'true' else 'false' end from dual;