Concerns that Sears is headed toward bankruptcy have been reignited.

The retailer’s shares tumbled more than 13 percent in early trading Wednesday, to below $8, hours after the struggling department store expressed doubt about its future as a retailer.

“Our historical operating results indicate substantial doubt exists related to the company’s ability to continue as a going concern,” Sears said in an annual filing with the Securities and Exchange Commission.

The comments followed what some investors saw as a better-than-expected fiscal fourth quarter, when Sears reported a narrower loss than the same period a year earlier.

The retailer also said at the time that it would use some of the proceeds from its asset sales to pay off its pension obligations, which have been burning through its cash. Those two factors lifted the company’s shares more than 15 percent that day.

Sears has been closing stores, selling off assets like its Craftsman brand and borrowing money from CEO Eddie Lampert to survive. In January, it outlined goals save $1 billion this year by closing stores and reorganizing the business, and to reduce its debt and pension obligations by $1.5 billion.

So far, its financial maneuvers haven’t been enough to reverse declines at the company’s core business. Sears revenue declined 12 percent last year, to $22.1 billion. They’ve tumbled 44 percent since 2012, when the company generated $39.9 billion in sales.

A Sears spokesman did not immediately respond to CNBC’s request for additional information.

Sears’ warning that it could go out of business was the first time it had expressed such concern in its annual 10-K filing. However, the timing makes sense.

In last year’s annual report, Sears noted that back in 2014, the Financial Accounting Standards Board issued an update that required management to “assess whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the financial statements are issued.”

If said doubt existed, the company was required to disclose it. That update went into effect in the first quarter of 2017.

“The adoption of the new standard is not expected to have a material impact on the Company’s consolidated financial position, results of operations, cash flows or disclosures,” according to the filing.

In addition to its declining sales and tired stores, Sears’ pension plan could jeopardize its future.

The retailer has already contributed some $4 billion to the plan over the past 12 years. It’s been particularly burdensome since 2009, following the “severe decline in the capital markets that occurred in the latter part of 2008.”

That resulted in “abnormally low interest rates, which continue to persist.” The company’s domestic pension expense was $288 million in 2016, $229 million in 2015 and $89 million in 2014. Back in 2008, it was $1 million, according to that year’s SEC filing.

Sears is obligated to pay $250 million from Stanley Black & Decker‘s purchase of Craftsman to the plan in three years. The plan also has a 15-year lien on future sales of those products.

The company has $13.2 billion in total liabilities, according to the SEC report. It has no short-term borrowings.