(CNN Money) — For years, Twitter has struggled to impress Wall Street investors with its lackluster user numbers.
But it turns out Twitter’s numbers were even worse than had been reported.
Twitter revealed Thursday that it has overstated its monthly active user numbers for years by mistakenly including a segment of users from third-party applications.
“These third-party applications used Digits, a software development kit of our now-divested Fabric platform, that allowed third-party applications to send authentication messages via SMS through our systems, which did not relate to activity on the Twitter platform,” the company explained in its earnings report.
As a result, Twitter revised its previously reported numbers down by 1 – 2 million users for each of the last three quarters. The error is said to date back all the way to the fourth quarter of 2014.
However, the snafu was overshadowed by what proved to be a strong quarter for the social network.
Twitter added four million users in the third quarter, after having failed to add any users in the second quarter. Twitter now has 330 million users globally.
The gains came mostly from its international markets, but Twitter did manage to grow its U.S. user base by one million as well. In the previous quarter, Twitter’s U.S. audience actually shrunk slightly.
Twitter also said it may be profitable in the upcoming fourth quarter, for the first time in its four years as a publicly traded company.
The stock spiked 9% in pre-market trading Thursday following its earnings report.