NET
17 I was glad about the arrival of Stephanus, Fortunatus, and Achaicus because they have supplied the fellowship with you that I lacked.
Darby
17 But I rejoice in the coming of Stephanas and Fortunatus and Achaicus; because *they* have supplied what was lacking on your part.
KJV
17 I am glad of the coming of Stephanas and Fortunatus and Achaicus: for that which was lacking on your part they have supplied.