Water Bucket In Dispenser?

[SnowAge]

Hey Forums, yesterday me and SlimeCrave were trying to make a Auto Nether Wart farm in our base yesterday. This farm includes Water bucket in the dispenser. Now we used to be able to put them in there before. Unfortunately we couldn't put the item in the dispenser and it said "you can not the put in there"
Now I understand why you couldn't put lava in there but why cant we put water bucket in there?

 

[Maarten]

Because they can still be used to grief.