Intel Corp. may become the Grinch who stole Christmas from large PC makers.

HP Inc. HPQ, +1.47%   and Dell Technologies Inc. DELL, -3.64%  both admitted Tuesday that they expect a negative impact on their future results as a result of chip shortages for which Intel apologized last week. Dell laid bare that the chip giant’s shortages have gotten worse, an issue that was not clear in the apology, since Intel INTC, -0.79%  reiterated its stronger-than-expected guidance for the fourth quarter.

“Intel CPU shortages have worsened quarter-over-quarter, the shortages are now impacting our commercial PC and premium consumer PC Q4 forecasted shipments,” Dell Vice Chairman Jeff Clarke said in an earnings conference call Tuesday afternoon.

Dell cut its forecast for fiscal 2020, which includes two months in the current calendar fourth quarter, typically the industry’s busiest quarter of the year, thanks to holiday shopping. Dell stock took a hit, falling from slight gains to a decline of 4% in after-hours trading.

HP’s PC business had revenue growth of 4% in the fiscal fourth quarter reported on Tuesday, which was slightly ahead of the industry growth rate, but HP said the supply shortages will “constrain” its sales in the current quarter, which will include two months of the holiday shopping season

“So we are assuming that the CPU supply will constrain our revenue in Q1, and if you think about it on a sequential basis, certainly in the personal systems business, we would expect to have declines from Q4 to Q1 above the normal seasonal patterns,” Steven Fieler, HP Chief Financial Officer, said in response to an analyst’s question. “That being said…this is more of a revenue impact than profit impact for the quarter, as we expect our mix should be better.”

HP still managed to hold on to its after-hours stock gains Tuesday, mostly because investors’ attention may be diverted to an unwanted takeover bid from Xerox Holdings Corp. XRX, +0.34% On the call, executives declined to discuss the $22-a-share offer from Xerox, which its board has rejected, and told analysts they would not answer any questions about Xerox.

Investors should be much more focused on CPU shortages than ridiculous acquisition attempts from a smaller company dreaming of a different future for its sinking printing business, though. Shortages of CPUs have hurt PC makers previously, and higher prices for memory chips two holiday seasons ago put a major damper on margins for electronics companies across the spectrum.

But the investors who should really worry right now are Intel’s. Advanced Micro Devices Inc. AMD, -0.66%  has already proved itself to be a more worthy rival to Intel than in its previous attempts to challenge the larger chip company, and any inability to service the two biggest American PC manufacturers in their most important period for sales could drive HP and Dell right into AMD’s waiting arms.

Right now, the concern is that Intel could give Dell and HP coal in their Christmas stockings, but the result could be a new Santa Claus next year for the PC makers.