House Speaker Paul D. Ryan (Wis.) attends a news conference following a GOP caucus meeting on July 24 on Capitol Hill in Washington. (Jacquelyn Martin/AP)

A new fact about House Speaker Paul D. Ryan has emerged, one that until recently, he didn’t even know himself.

Ryan, a practicing Catholic, is 3 percent Jewish. More precisely, he’s 3 percent Ashkenazi Jewish, with eastern European roots.

His family history was revealed during the filming of an upcoming season of PBS’s “Finding Your Roots With Henry Louis Gates Jr.,” a TV series in which famous guests learn about their ancestral histories.

At a TV critics event Tuesday, Gates, the show’s host and a professor at Harvard University, told reporters that Ryan was surprised, but proud of his previously unknown heritage, according to the Associated Press.

“You could have knocked him over with a feather and then he was very proud of it,” Gates said. “We don’t know who that Jewish person was, but we know it was on his mother’s German line, which makes sense. So somebody who was a Christian German slept with a Jewish German person and that’s where that came from.”

Gates said his research took him all the way back to Ryan’s 10th great-grandfather who was born in 1531 in Germany, AP reported.

Naturally, the news of Ryan’s Jewish roots sparked social media frenzy.

“Paul D. Ryan is the first Jewish speaker of the House,” Politico senior writer Jake Sherman joked.

Ryan’s press secretary AshLee Strong joined in the fun, retweeting Sherman and writing, “Breaking.”

While his heritage was only recently brought to light, Ryan has long voiced support for Israel. In 2016, in the wake of the Iran nuclear deal, he addressed the American Israel Public Affairs Committee and stressed that the United States needed to give Israel “more than vague assurances that we’ve got their back.”

In January last year, Ryan delivered an impassioned speech on the House floor in defense of a measure calling for the repeal of a U.N. Security Council Resolution condemning Israeli settlements on disputed land.

“I am stunned at what happened last month. Our government abandoned our ally Israel when she needed us the most,” Ryan said at the time.

Some reactions were less than welcoming.

“I’m sorry but no, we don’t want him,” Israeli American novelist Ayelet Waldman tweeted.

In a second tweet, Waldman wrote, “Yo, Jews, let’s take up a collection to refund him his 3%.”

Many echoed her sentiments.

Others, however, seemed to be more accepting.

“apparently @SpeakerRyan is 3% #jewish on his mothers’ side. that’s cool,” Rabbi Daniel Kraus tweeted.

“Welcome to the tribe,” another user wrote.

But, the revelation of Ryan’s ancestry is only modestly significant. According to Orthodox tradition, a person is only considered Jewish if they are born to a Jewish mother or if they formally convert to Judaism. However, in Reform Judaism, a person is Jewish if either parent is Jewish.

Ryan will appear in the fifth season of “Finding Your Roots With Henry Louis Gates Jr.,” set to premiere in January. The show’s other guests include Sen. Marco Rubio (R-Fla.), Seth Meyers and Ann Curry.

Clarification: An earlier version of this story said a person was considered Jewish if their mother was Jewish. That is true among Orthodox Jews. Either parent being Jewish will suffice for Reform Judaism.