Donald Trump is gaining ground on Hillary Clinton, a new poll finds.

The NBC News/Survey Monkey Weekly Election Tracking Poll finds Clinton with a mere four-point lead on Trump, 48 percent to 44 percent. The same poll last week found Clinton with a bigger lead, winning 48 percent of the voters to Trump’s 42 percent.

Clinton had a 10-point lead over Trump in the same poll five weeks ago.

When third-party candidates are factored in, Clinton’s lead slips further, with the Democrat garnering 42 percent of the vote, Trump 40 percent, Libertarian Gary Johnson getting 11 percent and Green Party candidate Jill Stein at 4 percent.

The poll finds Trump surging among independent voters, with the mogul trailing Clinton by only two points among those voters, 38 percent to 36 percent. Trump used to be down among independents by double digits, NBC reports. Voters who describe themselves as independent are thought to be crucial to winning the presidency.

Favorability ratings for the two main presidential candidates are similar (38 percent have a favorable view of Trump, 39 percent of Clinton). And the candidates share a similar unfavorable rating (60 percent view Trump unfavorably and 59 percent have that view of Clinton).

This week’s NBC News/SurveyMonkey online poll surveyed 16,220 registered voters and was taken between Sept. 5 and 11.