Eminem has an ominous warning for somebody.

Tweeting for the first time in a month, the 46-year-old seems to be preparing to take another rap game scalp.

People think they want this problem 'til they get it.

— Marshall Mathers (@Eminem) August 28, 2019

People think they want this problem 'til they get it," he typed.

As for who Em's target is ... Brand Nubian rapper and Vlad TV couch guest Lord Jamar -- who just can't keep Marshall's name out of his mouth -- comes to mind.

Jamar and Em's boy Royce Da 5'9" have been going back and forth over the merits of Shady and whether or not Jamar is obsessed with the more famous rapper.

Do you think Jamar's a big enough fish to attract Em's hook?