Ghast fireballs destroy basalt

According to Wiki, basalt should not be destroyed by ghast fireballs (seems logical, because, also according to Wiki, basalt has a blast resistance of 4.2, and ghast fireballs a blast damage of 4), but ghast fireball's do break basalt (I noticed when trying to build a shelter for a giant warped fungus farm).

Steps to Reproduce:

1. Build a wall out of basalt
2. Spawn a ghast
3. Let the ghast shoot a fireball at the wall

Observed Results:
The basalt is destroyed by the fireball.

Expected Results:
The basalt should not be destroyed by the fireball.