Election Assistance Commission chairman Matthew Masterson is being removed from his post by the White House and House Speaker Paul Ryan, according to a report from Reuters. Appointed to the commission in 2014 and serving as chairman since February, Masterson was expected to be appointed to a second four-year term.

It’s unclear why Masterson was removed, but the timing is likely to be a significant blow to the ongoing effort to secure voting machines against hacking. Less than nine months remain before the 2018 elections, and several types of voting machines remain vulnerable to remote hacking through remote-access software attacks and other vulnerabilities.

Observers expect Masterson’s replacement to be former prosecutor Christy McCormick, the other Republican member of the committee. In 2017, McCormick publicly criticized efforts to designate voting machines as critical infrastructure. In the same letter, she dismissed evidence that Russian agents were probing election infrastructure, describing the evidence as “disappointing, underwhelming, and thin.”

There’s still no evidence that hacking efforts altered any voter rolls in 2016, and the decentralized nature of US elections makes it difficult to significantly alter rolls without being detected. Still, there’s strong evidence of foreign powers probing voter rolls and election officials’ computers. In June, the Department of Homeland Security estimated that election systems in 21 different states were scanned in the run-up to the 2016 election, although no direct attacks were recorded.