Britney Spears fans are trolling Justin Timberlake on the music charts.

Timberlake released his long-awaited comeback single "Selfish" on Thursday (Jan. 25), but Spears fans weren't about to let his new song slide, and so they drove Spears' own song called "Selfish" up the charts — even though the song is 13 years old.

The fan initiative appears to have stemmed from a joke.

According to Entertainment Weekly, it all started when a Britney Spears stan account on Twitter (now known as X), jokingly tweeted, "Britney Spears will release her new single, 'Selfish,' this Thursday, January 25th" on Monday (Jan. 22).

Fans acted quickly, driving Spears' "Selfish" all the way up the iTunes chart to the top 10.

As of publishing, the song is currently sitting at No. 4 — only three spots below Timberlake's "Selfish," which is currently at No. 1.

A YouTube fan account confirmed to Entertainment Weekly that the initiative to drive Spears' song up the chart started as a joke after Timberlake announced his new single.

"Then we all joined in, saying that Britney Spears was coming back with a 'brand' new song. I still can't believe that it became so big, and we see the results we see now. We are all so happy to see her song making a comeback after all these years!" the account told Entertainment Weekly.

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"Selfish" appears on the deluxe version of Spears' 2011 album Femme Fatale. The song was never officially released as a single.

Timberlake's "Selfish" is the lead single off his upcoming album Everything I Thought It Was, out March 15.

Listen to Britney Spears' "Selfish":

Watch Justin Timberlake's "Selfish" Music Video:

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