The "mushroom fields" biome *sometimes* generate where there's little or no land.

What I expected to happen was...:
that the "mushroom fields" biome always generated on land. 

What actually happened was...:
the "mushroom fields" biome sometimes generate when there's little or no land. 

Steps to Reproduce:
1. Find the "mushroom fields" biome or do /locatebiome mushroom_fields