diff --git a/Makefile b/Makefile
index a6550ad0..4a3f798d 100644
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,9 @@ clean:
 test:
 	@dune runtest $(DUNE_OPTS)
 
+doc:
+	@dune build $(DUNE_OPTS) @doc
+
 WATCH?=@all
 watch:
 	dune build $(DUNE_OPTS) -w $(WATCH)
diff --git a/dune-project b/dune-project
index 1be733f3..65425345 100644
--- a/dune-project
+++ b/dune-project
@@ -24,6 +24,7 @@
   (ocaml (>= 4.08))
   dune
   either
+  (odoc :with-doc)
   (mdx
    (and
     (>= 1.9.0)
diff --git a/src/pool.mli b/src/pool.mli
index aa9b361c..0d6b28df 100644
--- a/src/pool.mli
+++ b/src/pool.mli
@@ -1,6 +1,7 @@
 (** Thread pool *)
 
 type t
+(** A pool of threads. *)
 
 type thread_loop_wrapper =
   thread:Thread.t -> pool:t -> (unit -> unit) -> unit -> unit