A container guide for preventing bottles or other containers from overturning as the bottles are loaded into cartons includes guide bars mounted above a container conveyor and in parallel alignment with lane dividers for directing bottles from the container conveyor and into the cartons, which are conveyed on a carton conveyor. The guide bars support the upper portions of the bottles as the bottles cross a potentially uneven transition region extending between the two conveyors and beyond the extent of the lane dividers. Each guide bar has a guiding edge for supporting the upper portion of the bottles, which may be tapered or shouldered thereby requiring the guiding edge to be offset somewhat from the lane dividers. Each guide bar also has an outfeed end that is relatively thinner than its infeed end to facilitate the outfeed end clearing the upper edges of the end flaps of the cartons.