diff --git a/API.md b/API.md
index cd03c2c..44becb9 100644
--- a/API.md
+++ b/API.md
@@ -98,4 +98,6 @@ The shapes are defined as follows:
 ## Biomes
 
 Just like the surface world, the underground world uses biomes to decorate their
-caves. The cave biomes are independent of 
\ No newline at end of file
+caves. The cave biomes are independent of the cave shapes.
+
+**Under development.**