Senate Democratic and Republican leaders on Wednesday may have struck a deal to reopen the government and extend its borrowing authority into next year, but a cloud of uncertainty still hovers over Washington. The U.S. won’t default on its debt, at least not this week, but that’s no reason to celebrate.

Under terms of the deal, the government is being funded through January 15, but the U.S. could hit the debt ceiling again in early February, leaving Americans vulnerable to another fight over the borrowing limit. For retailers, the timing couldn’t be worse. The January and February deadlines fall just after the busiest shopping months of the year, and the uncertainty of it all could weigh down holiday sales.

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This happened in 2012. Recall, U.S. holiday sales were the weakest since 2008 when the economy was in deep recession, partly due to the so-called fiscal cliff, a combination of tax hikes and government spending cuts that was scheduled to kick in at the start of 2013. In the weeks before the deadline, Congress struggled to strike a deal to avoid the cliff. Consumer confidence fell; retail sales in the two months before Christmas rose 0.7% from a year earlier, which was well below the 3% to 4% many analysts had expected for holiday sales.

Needless to say, far worse things could happen than fewer presents under the Christmas tree. If Congress is unable to raise the debt ceiling next year, defaulting on the nation’s debt could cause the U.S. dollar to collapse, investors could lose big, banks could lose more, borrowing costs could rise, and the U.S. economy could slip back to recession, dragging the rest of the world into economic chaos. And so on.

Nonetheless, retailers are incredibly important to the U.S. economy, which is driven largely by consumption. And the holiday season is critical for retailers big and small; on average, business in November and December accounts for 20% to 40% of a retailer’s annual sales and 20% of the industry’s total annual sales, according to the National Retail Federation, a trade association that represents U.S. retailers.

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This November and December, sales are expected to marginally increase 3.9% to $602.1 billion, slightly higher than last year’s 3.5% holiday season sales growth, NRF says. The estimates were released earlier this month, and the association has not updated its forecast since the government shutdown. Nonetheless, the U.S. enters the holiday shopping season after consumer confidence last week saw its sharpest one-week drop since the period following collapse of Lehman Brothers, according to Gallup.

On Thursday, NRF CEO Matthew Shay had sharp words for Congress.

“As we head into the holiday shopping season, retailers and consumers need stability and certainty from policymakers in Washington and assurance that the economy will not implode due to their actions or more important, lack thereof,” Shay said in a statement. “This new norm of legislating from crisis to crisis is no way to govern.”

And that’s how the debt ceiling could steal Christmas.