NEW YORK (AP) — Kohl’s says that recent offers to purchase the department store chain undervalue its business, and it is adopting a shareholder rights plan to head off any hostile takeovers.

The shareholder rights plan is effective immediately and expires in a year.

The move comes as Kohl’s has received multiple buyout offers in recent weeks. Private equity firm Sycamore Partners had reportedly approached Kohl’s about a potential deal last month.

A group called Acacia Research, backed by activist hedge fund Starboard Value LP, bid $64 per share, or about $9 billion. At the time the Menomonee Falls, Wisconsin-based retailer said that its board was reviewing the offers.