It was a c—kblock from Buckingham Palace.

The royal family reportedly blocked Meghan Markle from saying certain words on “Suits,” according to the show’s creator, Aaron Korsh — and a synonym for the word “rooster” may have been one.

“I will say, and I think Harry put this in the book, because I heard people talking about it — [the royal family] weighed in on some stuff,” Korsh revealed in an interview with the Hollywood Reporter on Tuesday.

“Not many things, by the way, but a few things that we wanted to do and couldn’t do, and it was a little irritating,” he added.

Korsh explained that Markle, 42, was supposed to deliver the line, “My family would say poppycock,” but the royal family had it nixed.

“The royal family did not want her saying the word,” Korsh claimed about the Palace. “They didn’t want to put the word ‘poppycock’ in her mouth. I presume because they didn’t want people cutting things together of her saying ‘c—k.’”

So what did they change it to? An actual curse word.

He revealed that they had to change “poppycock” to “bulls—t” instead, a switch he wasn’t a fan of.

The “Suits” creator wasn’t sure how the royal family got their hands on the scripts, but said they did, and that he became aware of their access because he would get “feedback.”

“There was maybe one or two more things, but I can’t remember,” he said of other changes.

Markle played paralegal-turned-attorney Rachel Zane on the show, about a fictional NYC law firm, from Season 1 in 2011 through Season 7.

Her final episode aired in April 2018 — just weeks before she tied the knotwith Prince Harry, 38.

However, Korsh noted that the Duchess wasn’t the one to tell him that she couldn’t deliver the line.

“No, Meghan did not call me,” he said. “I can’t remember. It might have been the directing producer at the time, or her agent. Whoever it was, they didn’t like having to tell me any more than I liked having to hear it.”

Korsh went on to explain that he wrote “poppycock” into the script as a “nod” to his family, who often used the old-fashioned slang term when discussing sensitive topics.

“I did not like it because I’d told my in-laws that [poppycock] was going to be in the show,” the creator admitted to the outlet.

However, Korsh said he was sympathetic to the change since he knows how internet trolls operate.

“I’m pretty sure it got explained to me that it was about that [splicing potential], I had some sympathy because I wouldn’t want somebody doing that to her either,” he said. “And the thing is, I didn’t think anybody really would, but also I don’t know. People are crazy.”

The Post reached out to representatives for Markle and Buckingham Palace for comment.

The off-the-air series has been having a bit of a renaissance lately after it became available to stream on Netflix in the US on June 17 — the same day as King Charles III’s 75th birthday parade, known as Trooping the Colour.

In its first week on Netflix alone, the show hit 3.1 billion viewing minutes and is currently ranked number six in the streamer’s weekly top 10.

Rules like the “poppycock” ban are not unheard of for the royal family. Over the years, some royal members have pulled back the curtain on Buckingham Palace’s protocols and revealed some of the things they’re not allowed to do.

In 2018, while appearing on “MasterChef Australia,” Queen Camilla confirmed that royal family members are not to eat garlic because of how often they have to talk to people.

And, this past April, Kate Middleton may have broken a rumored royal rule by wearing red nail polish to a church service on Easter Sunday.

It’s been widely reported that the late Queen Elizabeth II disapproved of bright nail polish, instead favoring Essie’s light pink lacquer, named “Ballet Slippers.”

And former royal chef Darren McGrady recently revealed to Harper’s Bazaar that Prince William and Kate’s children — Prince Louis, Princess Charlotte and Prince George — are not permitted to sit with their parents during official dinners and holidays, including Christmas.

“The children always ate in the nursery until they were old enough to conduct themselves properly at the dining table,” he said.