A lift cord spool assembly may be used in a motorized window treatment. The lift cord spool assembly may include a spool, a housing, and an end cap. The spool may be configured to windingly receive a lift cord of the motorized window treatment. A diameter of the spool may taper by approximately 0.5 degrees from the first end to an opposed second end. The housing may be configured to surround the spool. The end cap may be configured to attach to the housing, for example, such that the spool is retained within the housing. The end cap may include an inner surface, a shoulder, an aperture, and a guide. The guide may be configured to push the lift cord onto the spool as the lift cord is wound onto the spool. The guide may define a gradual slope around a circumference of the shoulder.