Player on moving object doesn't follow it Unity 5

I'm testing a moving object that moves back and forth, but when the player jumps on it, the player doesn't follow it (the object is moving extremely slow, so it's not sliding off because of speed.).

I've tried adding a rigidbody to the moving object, I've tried messing with the masses of both the moving object and player, as well as tried messing with the drags of the player (I got desperate, was trying anything).

If anyone can explain how to make it so the player will "follow", or stay on the moving object, I would be extremely grateful.