diff --git a/.merlin b/.merlin
index 4e4f3b4..4ac5fc8 100644
--- a/.merlin
+++ b/.merlin
@@ -1,2 +1,6 @@
-B _build
 S .
+S tests/
+B _build
+B _build/tests/
+PKG oUnit
+PKG bench
diff --git a/Makefile b/Makefile
index 3c06dfc..d4d255d 100644
--- a/Makefile
+++ b/Makefile
@@ -5,20 +5,19 @@ TARGETS = sequence.cma sequence.cmxa sequence.cmi sequence.a
 LIB = $(addprefix _build/, $(TARGETS)) 
 INSTALL = $(LIB) sequence.mli
 
-all:
+all: tests
 	ocamlbuild $(TARGETS) $(DOC)
 
 bench: all
-	ocamlbuild \
-		-cflags -I,`ocamlfind query extlib` \
-		-lflags -I,`ocamlfind query extlib` \
-		-package extlib -package unix bench.native
+	ocamlbuild -use-ocamlfind -pkg bench tests/benchs.native
 
 tests:
-	ocamlbuild tests.native
+	ocamlbuild -use-ocamlfind -pkg oUnit tests/run_tests.native
 
 install: all
 	ocamlfind install $(NAME) META $(INSTALL)
 
 clean:
 	ocamlbuild -clean
+
+.PHONY: all clean tests bench
diff --git a/README.md b/README.md
index 47fc47a..46323a0 100644
--- a/README.md
+++ b/README.md
@@ -19,12 +19,26 @@ You need OCaml, say OCaml 3.12 or OCaml 4.0.
 
     $ make
 
-To see how to use it, check `tests.ml`. `sequence.ml` has a few examples of how to convert
-data structures into sequences, and conversely.
+If you have `OUnit` installed, you can build and run tests with
 
-The module `sexpr.mli` exposes the interface of the S-expression example library. It
-requires OCaml>=4.0 to compile, because of the GADT structure used in the monadic
-parser combinators part of `sexpr.ml`.
+    $ make tests
+    $ ./run_tests.native
+
+If you have `Bench` installed, you can build and run benchmarks with
+
+    $ make benchs
+    $ ./benchs.native
+
+To see how to use the library, check the `examples` directory.
+`tests.ml` has a few examples of how to convert basic data structures into
+sequences, and conversely.
+
+Examples
+========
+
+The module `examples/sexpr.mli` exposes the interface of the S-expression
+example library. It requires OCaml>=4.0 to compile, because of the GADT
+structure used in the monadic parser combinators part of `examples/sexpr.ml`.
 
 Documentation
 =============
diff --git a/tests/run_tests.ml b/tests/run_tests.ml
new file mode 100644
index 0000000..0fa3d58
--- /dev/null
+++ b/tests/run_tests.ml
@@ -0,0 +1,9 @@
+
+open OUnit
+
+let suite =
+    "run_tests" >:::
+      [ Test_sequence.suite; ]
+
+let _ =
+  OUnit.run_test_tt_main suite
diff --git a/tests/test_sequence.ml b/tests/test_sequence.ml
new file mode 100644
index 0000000..bceddd2
--- /dev/null
+++ b/tests/test_sequence.ml
@@ -0,0 +1,17 @@
+
+open OUnit
+
+module S = Sequence
+
+let test_empty () =
+  let seq = S.empty in
+  OUnit.assert_bool "empty" (S.is_empty seq);
+  OUnit.assert_bool "empty"
+    (try S.iter (fun _ -> raise Exit) seq; true with Exit -> false);
+  ()
+
+let suite =
+  "test_sequence" >:::
+    [ "test_empty" >:: test_empty;
+      
+    ]