California Property Trust, the owner of the building that houses Twitter headquarters, is suing Elon Musk’s social media company for failing to pay $136,250 in rent. According to Bloomberg (via The Verge), the firm notified Twitter on December 16th that it would default on its lease for the 30th floor of the Hartford Building, located at 650 California Street in San Francisco, if it didn’t pay its outstanding rent within five days. In a complaint filed this week with the San Francisco County Superior Court, California Property Trust said Twitter failed to comply with the order.

According to a December 13th New York Times report, Twitter had in recent weeks stopped paying rent on all of its global offices to save on costs. The company also faces a lawsuit for failing to pay $197,725 for charter flights Musk took during his first week at Twitter. Over that same time period, Musk has reportedly brought over “more than half a dozen” lawyers from SpaceX to bolster Twitter’s legal team.