SUMMARY ORDER

Plaintiff-Appellant Vicki- Smithers, proceeding pro se, appeals from the District Court’s judgment dismissing her claims of employment discrimination against two United States Postal Service employees and the Postmaster General. The District Court dismissed Smithers’s claims on the ground of invalid service, holding that Smithers had failed to serve the United States in a proper and timely fashion, as required under Federal Rule of Civil Procedure 4(i). We assume the parties’ familiarity with the underlying facts, the procedural history of the case, and the issues on appeal.

On appeal, Smithers argues only the merits of her discrimination claims and does not address her failure to effect proper service. For that reason, we hold that *723 she has waived any challenge to the District Court’s determination that she failed to properly and timely serve process. See JP Morgan Chase Bank v. Altos Hornos de Mexico, S.A. de C.V., 412 F.3d 418, 428 (2d Cir. 2005) (“[Arguments not made in an appellant’s opening brief are waived...LoSacco v. City of Middletown, 71 F.3d 88, 92-93 (2d Cir. 1995) (explaining that a pro se appellant abandons an issue not raised in her appellate brief). Even if we excused Smithers’s failure to argue the service-of-process issue on appeal, which we have discretion to do “if manifest injustice would otherwise result,” JP Morgan Chase Bank, 412 F.3d at 428, the District Court’s decision was correct.

We review a dismissal for improper service under Federal Rule of Civil Procedure 12(b)(5) for abuse of discretion. See Dickerson v. Napolitano, 604 F.3d 732, 740 (2d Cir. 2010). In the context of a dismissal pursuant to Rule 12(b)(5), a plaintiff bears the burden of establishing adequate service. See id, at 752. The District Court was correct to dismiss Smithers’s claim on the ground of improper service because Smith-ers made no reasonable effort to effect proper service. See id. at 753.

Nevertheless, the District Court failed to specify that its dismissal of Smithers’s claims was without prejudice, as required under Federal Rule of Civil Procedure 4(m). Remand is not necessary, however, because we have authority to modify the judgment to specify that dismissal was without prejudice. See U.S. ex rel. Pilon v. Martin Marietta Corp., 60 F.3d 995, 1000 (2d Cir. 1995).

CONCLUSION

Accordingly, the District Court’s February 3, 2016 judgment is MODIFIED to provide that Smithers’s complaint is dismissed without prejudice, and is AFFIRMED as modified.