My employer mistakenly put 2 dependents on my W4 instead of 1 so what do I do to correct this so I can get the correct amount of money back on my taxes when I file !

I worked two jobs for the same amount of time last year and for the first job I will be getting back $756.30 with 1 dependent but on the second job they mistakenly put on my W4 that I have 2 dependents instead of 1 so on my W2 it says I will only be getting back $88 but that isn't right it should be the same as the other job how do I get this corrected before I file my taxes ?