An overfeed roller assembly for use on a rotating drive shaft of a textile machine is adapted for adjusting downstream tension in a continuous moving length of yarn. The overfeed roller assembly comprises a base assembly designed for mounting on the drive shaft, and an annular yarn tension adjuster carried by the base assembly. The tension adjuster comprises opposing closely spaced yarn-contacting walls. The yarn-contacting walls define a shallow generally serpentine depression in the tension adjuster adapted for receiving the continuous moving length of yarn. Yarn tension downstream of the roller assembly is thereby reduced as the moving yarn meanders through the tension adjuster in frictional contact with the yarn-contacting walls of the serpentine depression.