Democratic U.S. presidential candidate Hillary Clinton’s aides debated on including jokes about her private email server in several of her speeches, hacked emails published by WikiLeaks last week revealed. Clinton’s use of a private email server while serving as the secretary of state came to light in March 2015.

The emails leaked by the transparency group showed Clinton and her aides believed the controversy would blow over soon but instead it became a massive political challenge in her fight for presidency.

According to the emails, Director of Communications for Clinton’s campaign Jennifer Palmieri suggested in March 2015 that Clinton make jokes about her use of a private email server at a dinner hosted by EMILY’s List, a political action committee. However, Clinton’s Press Secretary Nick Merrill responded: “I don’t think it’s nuts if we can come up with the right thing. But it could also be nuts.”

The campaign discussed the possibility of cracking a joke until political consultant Mandy Grunwald brought the train to a grinding halt after speaking to Jim Margolis, a media adviser to the campaign.

“We don’t know what’s in the emails, so we are nervous about this. Might get a big laugh tonight and regret it when content of emails is disclosed,” Grunwald wrote.

In August 2015, Clinton’s director of speechwriting, Dan Schwerin, raised the topic again when he shared a draft of an address at an annual Iowa political event asking for input from his colleagues.

“I look forward to your feedback. (Also, if anyone has a funny email/server joke, please send it my way.),” Schwerin wrote in the email.

WikiLeaks has dumped several batches of emails hacked from accounts of Clinton aide John Podesta in recent weeks. The group has promised to dump more information well beyond the elections. Clinton’s campaign has not confirmed the authenticity of these emails and has accused the transparency group of working with Russia to benefit the Republican nominee, Donald Trump.