A yarn lap preventor for mounting in an open end spinning machine to deflect a parted yarn end away from an enlarged diameter area of a rotating take-up shaft of the open end spinning machine. The yarn lap preventor is preferably integrally molded plastic including a body portion connected to a base mounting portion. The body portion of the yarn lap preventor includes a tapered edge which is positioned adjacent the enlarged diameter area of the take-up shaft. The body portion also includes a shield portion which extends along an arcuate portion of the enlarged diameter area. The base mounting portion includes a slotted opening to facilitate mounting with an existing fastener, such as the fastening screw which secures a yarn guide eyelet mounting plate to a traverse bar. A method for preventing the accumulation of yarn laps is also disclosed which includes deflecting a parted yarn and shielding the enlarged diameter area of the take-up shaft from the parted yarn end. The method for retrofitting an existing open end spinning machine includes using an existing fastener adjacent the enlarged diameter area of the take-up shaft.