```{index} single: unlock_keys; Hash::Util function ``` ```{index} single: Hash::Util::unlock_keys; Perl function ``` # unlock_keys Lift the keyset restriction imposed by `lock_keys`. ## Synopsis unlock_keys(%hash); Any keys locked with `lock_value` or `lock_hash` remain locked — this undoes only the keyset restriction. Hidden placeholder keys introduced while the hash was locked stay in place; use `hidden_keys` to see them and ordinary assignment to bring them into the visible keyset. Returns a reference to the hash.