diff --git a/src/serde/de.rs b/src/serde/de.rs
index f2a3783..616d529 100644
--- a/src/serde/de.rs
+++ b/src/serde/de.rs
@@ -1,3 +1,5 @@
+//! Deserialize Lua values to a Rust data structure.
+
 use std::cell::RefCell;
 use std::os::raw::c_void;
 use std::rc::Rc;
diff --git a/src/serde/ser.rs b/src/serde/ser.rs
index 1292e4d..a6cac26 100644
--- a/src/serde/ser.rs
+++ b/src/serde/ser.rs
@@ -1,3 +1,5 @@
+//! Serialize a Rust data structure into Lua value.
+
 use serde::{ser, Serialize};
 
 use super::LuaSerdeExt;