Fireballs don't light armor stands on fire

When firing a Fire Charge out of a Dispenser at any mob, it sets it on fire. However when a Fire Charge is shot out of a Dispenser at an Armor Stand, it is not set on fire. This edge case seems to make the behaviour of the Fire Charge inconsistent.

How to reproduce:

1. Place an armor stand.
2. Place a dispenser facing the armor stand, a few blocks away from it.
3. Insert fire charges into the dispenser.
4. Power the dispenser.

Expected result:

Armor stands would be lit on fire by fireballs.

Observed result:

Armor stands are not lit on fire by fireballs.