diff --git a/lib/http_signatures/http_signatures.ex b/lib/http_signatures/http_signatures.ex
index 25bc9f1..018ee2e 100644
--- a/lib/http_signatures/http_signatures.ex
+++ b/lib/http_signatures/http_signatures.ex
@@ -4,6 +4,10 @@
 
 # https://tools.ietf.org/html/draft-cavage-http-signatures-08
 defmodule HTTPSignatures do
+  @moduledoc """
+  HTTP Signatures library.
+  """
+
   require Logger
 
   def split_signature(sig) do
diff --git a/test/support/test_adapter.ex b/test/support/test_adapter.ex
index 01e173f..58b9b4b 100644
--- a/test/support/test_adapter.ex
+++ b/test/support/test_adapter.ex
@@ -5,6 +5,8 @@
 defmodule HTTPSignatures.TestAdapter do
   @behaviour HTTPSignatures.Adapter
 
+  @moduledoc "Test adapter for HTTPSignatures library."
+
   @mastodon_admin_pubkey hd(
                            :public_key.pem_decode(
                              File.read!("test/admin@mastodon.example.org.key")