"belowName" score display always shows 0

The "belowName" score display always shows 0, no matter what the score actually is.

How to Reproduce:
1. /scoreboard objectives add <objective> <criteria>
2. /scoreboard objectives setdisplay belowName <objective>
3. /scoreboard players set <player> <objective> 7

The display should show 7, but it shows 0.