diff --git a/src/ffi.rs b/src/ffi.rs
index f5dbb48..6f14190 100644
--- a/src/ffi.rs
+++ b/src/ffi.rs
@@ -1,3 +1,5 @@
+//! Bindings to this library to allow it to be called from C/C++.
+
 use libc::{c_char, c_float};
 use std::{
     cell::RefCell,