It was a simple tweak — just two words.

But with that, Canada voted to turn its national anthem “O Canada” gender neutral, delighting liberal lawmakers and infuriating conservatives.

The offending line — “in all thy sons command” — was switched to “in all of us command.”

Prime Minister Justin Trudeau tweeted: “another positive step towards gender equality.”

The Canadian anthem was composed by judge and poet Robert Stanley Weir in 1908. His original did not include the offending line, which was added by Weir after World War I to reference the men who lost their lives in battle.

Shortly after the vote Wednesday, the bill’s proponents celebrated.

“I’m very, very happy,” Independent Ontario Sen. Frances Lankin, who sponsored the measure, told the Canadian Broadcasting Corp. “This may be small, it’s about two words, but it’s huge ... we can now sing it with pride knowing the law will support us in terms of the language. I’m proud to be part of the group that made this happen.”

Not everyone was quite so excited.

Conservative senators opposed the measure, arguing that Parliament had no business tweaking a century-old song decades after its author passed away.

“Clearly, I’m disappointed ... it’s been a long fight, I believe the Canadian public wanted a say in our national anthem,” Sen. Don Plett told the CBC.

The change has been years in the making.

Lawmaker Mauril Belanger began pushing for the change in 1980. Since then, he’s introduced 12 bills to strip the text of its gendered language. All of his efforts failed. Then, after he was diagnosed with Lou Gehrig's disease, also called amyotrophic lateral sclerosis, ALS, in 2015, his project began to gain traction.