In a public letter released on Sunday, HP Inc CEO Enrique Lores and the company’s board chair Chip Bergh said that Xerox’s proposed bid “significantly undervalues HP and is not in the best interests of HP shareholders.”

Xerox originally offered HP an unsolicited bid to take over the company for $22 a share in a deal worth over $30 billion. Xerox management believed that the deal would benefit both companies and bolster their respective copy machine businesses, ultimately resulting in “cost synergies of at least $2.0 billion,” according to the original proposal letter, which HP also publicly released.

But in order for Xerox to acquire HP, a much larger company whose market capitalization is over three times the size of Xerox, the copy-machine giant would have had to raise a significant amount of financing. HP’s board questioned the “potential impact of outsized debt levels on the combined company’s stock” that would potentially result if Xerox carried forth with its financing plans.

HP also questioned the fundamental health of Xerox’s business and noted “the decline of Xerox’s revenue from $10.2 billion to $9.2 billion(on a trailing 12-month basis) since June 2018.” Although HP isn’t the major technology force as it was in previous decades, it’s still a massive business and has managed to grow annual sales by 13% to $58.5 billion over a three-year period ending in its fiscal 2018.

It should be noted that HP said it is still “open to exploring” a potential combination with Xerox, but it wants to do a more “rigorous analysis of the achievable synergies from a potential combination.”   

“With substantive engagement from Xerox management and access to diligence information on Xerox, we believe that we can quickly evaluate the merits of a potential transaction,” Lores and Bergh wrote. “We remain ready to engage with you to better understand your business and any value to be created from a combination.

Last week, activist investor Carl Ichahn revealed that he owns a 4.24% stake in HP, which is noteworthy considering he also owns a 10.6% stake in Xerox. Some analysts believed Ichahn was orchestrating Xerox’s plans to takeover HP, but Ichahn said Xerox’s board was handling the proposed deal on its own.

That said, Ichahn said that “a combination is a no-brainer,” however he didn’t specifically cite Xerox’s proposal to buy HP as the only possible deal that would make sense between the two companies. 

Fortune contacted Xerox and will update this story if it responds.

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