Pistons break redstone after reseting

Game lets you put redstone on-top of pistons but when pistons retract the redstone breaks.

What I expected to happen was...:
The redstone stays on the piston during the whole process

What actually happened was...:
When the piston retracted after redstone de-activates the redstone (that is directly ontop) breaks.

Steps to Reproduce:
1. Put redstone on piston
2. Power piston
3. De-power piston
= Redstone breaks