The world grieved on Friday upon hearing that beloved actor Leonard Nimoy, most famous for playing Spock on Star Trek, had died.

Many took to social media to express their condolences, but the Canadian Design Resource (CDR) led a call to action, encouraging Canadians to "Spock" their $5 bills.

"Spock" your $5 bills for Leonard Nimoy pic.twitter.com/bKdKyC3l4q — Design Canada (@The_CDR) February 27, 2015

With a pen and a little bit of time, former Canadian Prime Minister Sir Wilfrid Laurier, who is featured on the Canadian $5 bill, can pass as a pretty convincing Spock.

Leonard Nimoy as Spock on 'Star Trek'.

"This series of Canadian bills was an easy target," CDR’s publisher Todd Falkowsky told Quartz. "The existing portraits are quite large and can be improvised with easily, and the color of our $5s are the same blue as Spock’s uniform."

"Spocking Fives," as it's called, is nothing new. Canadians have been altering their $5 bills for years, according to the Huffington Post. Even after the banknote's design changed in 2013, some were still able to transform Laurier into Spock.

Of course, as some Twitter users pointed out, defacing currency in Canada may not be completely legal. The Royal Canadian Mint's website does specify that "The Currency Act and The Canadian Criminal Code clearly state that no person shall melt down, break up or use otherwise than as currency any coin that is legal tender in Canada." However, the law does not specify the defacing of banknotes.

Still, a Bank of Canada spokeswoman wrote in 2002 that it "strongly objects to any mutilation or defacement of banknotes." Writing on banknotes limits the life of the bills, she said, which costs taxpayers money.

Regardless, the spokeswoman added that banknotes with markings are still legal tender, and may be used in commercial transactions.

Update, March 2, 2015, 11:00 a.m. ET: A representative for the Bank of Canada responded to Masahble's request for information on the legality of defacing bills.