diff --git a/rust/hg-core/src/filepatterns.rs b/rust/hg-core/src/filepatterns.rs
--- a/rust/hg-core/src/filepatterns.rs
+++ b/rust/hg-core/src/filepatterns.rs
@@ -1,3 +1,12 @@
+// filepatterns.rs
+//
+// Copyright 2019 Raphaël Gomès <rgomes@octobus.net>
+//
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2 or any later version.
+
+//! Handling of Mercurial-specific patterns.
+
 use crate::{LineNumber, PatternError, PatternFileError};
 use regex::bytes::Regex;
 use std::collections::HashMap;
diff --git a/rust/hg-core/src/utils/files.rs b/rust/hg-core/src/utils/files.rs
--- a/rust/hg-core/src/utils/files.rs
+++ b/rust/hg-core/src/utils/files.rs
@@ -1,3 +1,14 @@
+// files.rs
+//
+// Copyright 2019
+// Raphaël Gomès <rgomes@octobus.net>,
+// Yuya Nishihara <yuya@tcha.org>
+//
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2 or any later version.
+
+//! Functions for fiddling with files.
+
 use std::iter::FusedIterator;
 use std::path::Path;
 
diff --git a/rust/hg-core/src/utils/mod.rs b/rust/hg-core/src/utils/mod.rs
--- a/rust/hg-core/src/utils/mod.rs
+++ b/rust/hg-core/src/utils/mod.rs
@@ -1,3 +1,12 @@
+// utils module
+//
+// Copyright 2019 Raphaël Gomès <rgomes@octobus.net>
+//
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2 or any later version.
+
+//! Contains useful functions, traits, structs, etc. for use in core.
+
 pub mod files;
 
 pub fn replace_slice<T>(buf: &mut [T], from: &[T], to: &[T])