What's the best way to patch a hole in the seam of a raft?

I've patched multiple holes in inflatable things using just duct tape or on the occasion, an actual kit designed for patching holes and having it work and hold up just fine, but whenever the hole happens to be on the seam of the rubber, my methods just don't seem to work out so well. If it's on the seam, is it better to just use glue to cover the hole, or is there a special technique for taping up/patching up a hole in in the seam?