diff --git a/doc/docs.md b/doc/docs.md
index 9d03dd1f39..0fe01b3a4b 100644
--- a/doc/docs.md
+++ b/doc/docs.md
@@ -1704,6 +1704,7 @@ fn main() {
 ```
 
 * Module names should be short, under 10 characters.
+* Module names must use `snake_case`.
 * Circular imports are not allowed.
 * You can have as many .v files in a module as you want.
 * You can create modules anywhere.