Pufferfish behavior issues (jumps out of 1x1 water block and kills itself)

I was trying to make a door using the pufferfish behavior mechanics where it will puff up when a player is near. using a 1x1 block of water the pufferfish will just sit there in its puffed up state and when you place in on a half slab with water on it (which you have to do for the door)the fish jumps out and kills itself