diff --git a/containers.opam b/containers.opam
index 333d4a28..179fede2 100644
--- a/containers.opam
+++ b/containers.opam
@@ -18,7 +18,7 @@ depends: [
   "either" # compat
   "qtest" { with-test }
   "qcheck" { >= "0.14" & with-test }
-  "ounit" { with-test }
+  "ounit2" { with-test }
   "iter" { with-test }
   "gen" { with-test }
   "csexp" { with-test }
diff --git a/src/core/CCHeap.ml b/src/core/CCHeap.ml
index 69d0cc64..0b986f91 100644
--- a/src/core/CCHeap.ml
+++ b/src/core/CCHeap.ml
@@ -40,25 +40,25 @@ end
 (*$R
   let h = H.of_list [5;3;4;1;42;0] in
   let h, x = H.take_exn h in
-  OUnit.assert_equal ~printer:string_of_int 0 x;
+  OUnit2.assert_equal ~printer:string_of_int 0 x;
   let h, x = H.take_exn h in
-  OUnit.assert_equal ~printer:string_of_int 1 x;
+  OUnit2.assert_equal ~printer:string_of_int 1 x;
   let h, x = H.take_exn h in
-  OUnit.assert_equal ~printer:string_of_int 3 x;
+  OUnit2.assert_equal ~printer:string_of_int 3 x;
   let h, x = H.take_exn h in
-  OUnit.assert_equal ~printer:string_of_int 4 x;
+  OUnit2.assert_equal ~printer:string_of_int 4 x;
   let h, x = H.take_exn h in
-  OUnit.assert_equal ~printer:string_of_int 5 x;
+  OUnit2.assert_equal ~printer:string_of_int 5 x;
   let h, x = H.take_exn h in
-  OUnit.assert_equal ~printer:string_of_int 42 x;
-  OUnit.assert_raises H.Empty (fun () -> H.take_exn h);
+  OUnit2.assert_equal ~printer:string_of_int 42 x;
+  OUnit2.assert_raises H.Empty (fun () -> H.take_exn h);
 *)
 
 (*$QR & ~count:30
   Q.(list_of_size Gen.(return 1_000) int) (fun l ->
     (* put elements into a heap *)
     let h = H.of_iter (Iter.of_list l) in
-    OUnit.assert_equal 1_000 (H.size h);
+    OUnit2.assert_equal 1_000 (H.size h);
     let l' = extract_list h in
     is_sorted l'
   )
@@ -70,7 +70,7 @@ end
     (* put elements into a heap *)
     let h = H.of_iter (Iter.of_list l) in
     let h = H.filter (fun x->x mod 2=0) h in
-    OUnit.assert_bool "all odd"
+    OUnit2.assert_bool "all odd"
       (H.to_iter h |> Iter.for_all (fun x -> x mod 2 = 0));
     let l' = extract_list h in
     is_sorted l'
diff --git a/src/core/CCIO.ml b/src/core/CCIO.ml
index 36d03d7d..8bc329c0 100644
--- a/src/core/CCIO.ml
+++ b/src/core/CCIO.ml
@@ -170,13 +170,14 @@ let read_all ?(size=1024) ic = read_all_ ~op:Ret_string ~size ic
 (*$R
   let s = String.make 200 'y' in
   let s = Printf.sprintf "a\nb\n %s\nlast line\n" s in
-  OUnit.bracket_tmpfile ~prefix:"test_containers" ~mode:[Open_creat; Open_trunc]
-    (fun (name, oc) ->
+  File.with_temp ~prefix:"test_containers" ~suffix:""
+    (fun name ->
+      with_out name @@ fun oc ->
       output_string oc s;
       flush oc;
       let s' = with_in name read_all in
-      OUnit.assert_equal ~printer:(fun s->s) s s'
-    ) ()
+      OUnit2.assert_equal ~printer:(fun s->s) s s'
+    )
 *)
 
 
@@ -237,12 +238,13 @@ let write_lines_l oc l =
 (*$QR
    Q.(list_of_size Gen.(0 -- 40) printable_string) (fun l ->
      let l' = ref [] in
-     OUnit.bracket_tmpfile ~prefix:"test_containers" ~mode:[Open_creat; Open_trunc]
-      (fun (name, oc) ->
+     File.with_temp ~prefix:"test_containers" ~suffix:""
+      (fun name ->
+        with_out name @@ fun oc ->
         write_lines_l oc l;
         flush oc;
         l' := with_in name read_lines_l;
-      ) ();
+      );
      String.concat "\n" l = String.concat "\n" !l'
     )
 *)
@@ -250,12 +252,13 @@ let write_lines_l oc l =
 (*$QR
    Q.(list_of_size Gen.(0 -- 40) printable_string) (fun l ->
      let l' = ref [] in
-     OUnit.bracket_tmpfile ~prefix:"test_containers" ~mode:[Open_creat; Open_trunc]
-      (fun (name, oc) ->
+     File.with_temp ~prefix:"test_containers" ~suffix:""
+      (fun name ->
+        with_out name @@ fun oc ->
         write_lines oc (Gen.of_list l);
         flush oc;
         l' := with_in name (fun ic -> read_lines_gen ic |> Gen.to_list);
-      ) ();
+      );
      String.concat "\n" l = String.concat "\n" !l'
     )
 *)
@@ -288,16 +291,18 @@ let copy_into ?(bufsize=4_096) ic oc : unit =
 (*$QR
    Q.(list_of_size Gen.(0 -- 40) printable_string) (fun l ->
      let s = ref "" in
-     OUnit.bracket_tmpfile ~prefix:"test_containers1" ~mode:[Open_creat; Open_trunc]
-      (fun (name1, oc1) ->
+     File.with_temp ~prefix:"test_containers1" ~suffix:""
+      (fun name1 ->
+        with_out name1 @@ fun oc1 ->
         write_gen ~sep:"" oc1 (Gen.of_list l);
         flush oc1;
-        OUnit.bracket_tmpfile ~prefix:"test_containers2" ~mode:[Open_creat; Open_trunc]
-          (fun (name2, oc2) ->
+        File.with_temp ~prefix:"test_containers2" ~suffix:""
+          (fun name2 ->
+             with_out name2 @@ fun oc2 ->
              CCIO.with_in name1 (fun ic1 -> copy_into ic1 oc2);
              flush oc2;
-             s := with_in name2 read_all;) ();
-      ) ();
+             s := with_in name2 read_all;);
+      );
      String.concat "" l = !s
     )
 *)
@@ -390,7 +395,7 @@ module File = struct
     else gen_singleton (`File, d)
 
   (*$R
-    OUnit.assert_bool "walk categorizes files"
+    OUnit2.assert_bool "walk categorizes files"
       (File.walk "."
         |> Gen.for_all
           (function
diff --git a/src/core/CCList.ml b/src/core/CCList.ml
index 23fb0dec..af9cb738 100644
--- a/src/core/CCList.ml
+++ b/src/core/CCList.ml
@@ -1349,7 +1349,7 @@ let join ~join_row s1 s2 : _ t =
     if string_of_int i = j then Some (string_of_int i ^ " = " ^ j) else None
   in
   let s = join ~join_row s1 s2 in
-  OUnit.assert_equal ["1 = 1"; "2 = 2"] s;
+  OUnit2.assert_equal ["1 = 1"; "2 = 2"] s;
 *)
 
 let join_by (type a) ?(eq=Stdlib.(=)) ?(hash=Hashtbl.hash) f1 f2 ~merge c1 c2 =
diff --git a/src/core/CCVector.ml b/src/core/CCVector.ml
index 77fb42fa..8d512537 100644
--- a/src/core/CCVector.ml
+++ b/src/core/CCVector.ml
@@ -170,10 +170,10 @@ let[@inline] clear v =
 
 (*$R
   let v = of_iter Iter.(1 -- 10) in
-  OUnit.assert_equal 10 (size v);
+  OUnit2.assert_equal 10 (size v);
   clear v;
-  OUnit.assert_equal 0 (size v);
-  OUnit.assert_bool "empty_after_clear" (Iter.is_empty (to_iter v));
+  OUnit2.assert_equal 0 (size v);
+  OUnit2.assert_bool "empty_after_clear" (Iter.is_empty (to_iter v));
 *)
 
 let clear_and_reset v =
@@ -187,9 +187,9 @@ let clear_and_reset v =
   push v ("hello"^"world");
   Weak.set a 0 (Some (get v 0));
   Gc.full_major(); Gc.compact();
-  OUnit.assert_bool "is alive" (Weak.check a 0);
+  OUnit2.assert_bool "is alive" (Weak.check a 0);
   Gc.full_major(); Gc.compact();
-  OUnit.assert_equal None (Weak.get a 0);
+  OUnit2.assert_equal None (Weak.get a 0);
 *)
 
 let[@inline] is_empty v = v.size = 0
@@ -295,9 +295,9 @@ let append a b =
   let a = of_iter Iter.(1 -- 5) in
   let b = of_iter Iter.(6 -- 10) in
   append a b;
-  OUnit.assert_equal 10 (size a);
-  OUnit.assert_equal (Iter.to_array Iter.(1 -- 10)) (to_array a);
-  OUnit.assert_equal (Iter.to_array Iter.(6 -- 10)) (to_array b);
+  OUnit2.assert_equal 10 (size a);
+  OUnit2.assert_equal (Iter.to_array Iter.(1 -- 10)) (to_array a);
+  OUnit2.assert_equal (Iter.to_array Iter.(6 -- 10)) (to_array b);
 *)
 
 let[@inline] get v i =
@@ -525,12 +525,12 @@ let[@inline] copy v = {
 
 (*$R
   let v = of_iter Iter.(1 -- 100) in
-  OUnit.assert_equal 100 (size v);
+  OUnit2.assert_equal 100 (size v);
   let v' = copy v in
-  OUnit.assert_equal 100 (size v');
+  OUnit2.assert_equal 100 (size v');
   clear v';
-  OUnit.assert_bool "empty" (is_empty v');
-  OUnit.assert_bool "not_empty" (not (is_empty v));
+  OUnit2.assert_bool "empty" (is_empty v');
+  OUnit2.assert_bool "not_empty" (not (is_empty v));
 *)
 
 (*$QR
@@ -551,7 +551,7 @@ let truncate v n =
 (*$R
   let v = of_iter Iter.(1 -- 10) in
   truncate v 5;
-  OUnit.assert_equal [1;2;3;4;5] (to_list v);
+  OUnit2.assert_equal [1;2;3;4;5] (to_list v);
 *)
 
 (*$QR
diff --git a/src/data/CCDeque.ml b/src/data/CCDeque.ml
index 23bbabab..9488cf33 100644
--- a/src/data/CCDeque.ml
+++ b/src/data/CCDeque.ml
@@ -129,14 +129,14 @@ let peek_front d = match peek_front_opt d with
 (*$R
   let d = of_iter Iter.(1 -- 10) in
   let printer = pint in
-  OUnit.assert_equal ~printer 1 (peek_front d);
+  OUnit2.assert_equal ~printer 1 (peek_front d);
   push_front d 42;
-  OUnit.assert_equal ~printer 42 (peek_front d);
-  OUnit.assert_equal ~printer 42 (take_front d);
-  OUnit.assert_equal ~printer 1 (take_front d);
-  OUnit.assert_equal ~printer 2 (take_front d);
-  OUnit.assert_equal ~printer 3 (take_front d);
-  OUnit.assert_equal ~printer 10 (peek_back d);
+  OUnit2.assert_equal ~printer 42 (peek_front d);
+  OUnit2.assert_equal ~printer 42 (take_front d);
+  OUnit2.assert_equal ~printer 1 (take_front d);
+  OUnit2.assert_equal ~printer 2 (take_front d);
+  OUnit2.assert_equal ~printer 3 (take_front d);
+  OUnit2.assert_equal ~printer 10 (peek_back d);
 *)
 
 let peek_back_opt d =
@@ -159,14 +159,14 @@ let peek_back d = match peek_back_opt d with
 (*$R
   let d = of_iter Iter.(1 -- 10) in
   let printer = pint in
-  OUnit.assert_equal ~printer 1 (peek_front d);
+  OUnit2.assert_equal ~printer 1 (peek_front d);
   push_back d 42;
-  OUnit.assert_equal ~printer 42 (peek_back d);
-  OUnit.assert_equal ~printer 42 (take_back d);
-  OUnit.assert_equal ~printer 10 (take_back d);
-  OUnit.assert_equal ~printer 9 (take_back d);
-  OUnit.assert_equal ~printer 8 (take_back d);
-  OUnit.assert_equal ~printer 1 (peek_front d);
+  OUnit2.assert_equal ~printer 42 (peek_back d);
+  OUnit2.assert_equal ~printer 42 (take_back d);
+  OUnit2.assert_equal ~printer 10 (take_back d);
+  OUnit2.assert_equal ~printer 9 (take_back d);
+  OUnit2.assert_equal ~printer 8 (take_back d);
+  OUnit2.assert_equal ~printer 1 (peek_front d);
 *)
 
 let take_back_node_ n = match n.cell with
@@ -365,7 +365,7 @@ let iter f d =
   let d = of_iter Iter.(1 -- 5) in
   let s = Iter.from_iter (fun k -> iter k d) in
   let l = Iter.to_list s in
-  OUnit.assert_equal ~printer:plist [1;2;3;4;5] l;
+  OUnit2.assert_equal ~printer:plist [1;2;3;4;5] l;
 *)
 
 let append_front ~into q = iter (push_front into) q
@@ -411,7 +411,7 @@ let length d = d.size
 
 (*$R
   let d = of_iter Iter.(1 -- 10) in
-  OUnit.assert_equal ~printer:pint 10 (length d)
+  OUnit2.assert_equal ~printer:pint 10 (length d)
 *)
 
 type 'a iter = ('a -> unit) -> unit
diff --git a/src/data/CCFQueue.ml b/src/data/CCFQueue.ml
index efa65451..443abdbb 100644
--- a/src/data/CCFQueue.ml
+++ b/src/data/CCFQueue.ml
@@ -36,7 +36,7 @@ let empty : type a. a t = Shallow Zero
 
 (*$R
   let q = empty in
-  OUnit.assert_bool "is_empty" (is_empty q)
+  OUnit2.assert_bool "is_empty" (is_empty q)
 *)
 
 exception Empty
@@ -95,7 +95,7 @@ let rec snoc : type a. a t -> a -> a t
   let q = tail q in
   let q = List.fold_left snoc q [6;7;8] in
   let l = Iter.to_list (to_iter q) in
-  OUnit.assert_equal ~printer:pp_ilist [2;3;4;5;6;7;8] l
+  OUnit2.assert_equal ~printer:pp_ilist [2;3;4;5;6;7;8] l
 *)
 
 let rec take_front_exn : 'a. 'a t -> ('a *'a t)
@@ -124,11 +124,11 @@ let rec take_front_exn : 'a. 'a t -> ('a *'a t)
 (*$R
   let q = of_list [1;2;3;4] in
   let x, q = take_front_exn q in
-  OUnit.assert_equal 1 x;
+  OUnit2.assert_equal 1 x;
   let q = List.fold_left snoc q [5;6;7] in
-  OUnit.assert_equal 2 (first_exn q);
+  OUnit2.assert_equal 2 (first_exn q);
   let x, q = take_front_exn q in
-  OUnit.assert_equal 2 x;
+  OUnit2.assert_equal 2 x;
 *)
 
 let take_front q =
@@ -363,7 +363,7 @@ let append q1 q2 =
   let q2 = of_iter (Iter.of_list [5;6;7;8]) in
   let q = append q1 q2 in
   let l = Iter.to_list (to_iter q) in
-  OUnit.assert_equal ~printer:pp_ilist [1;2;3;4;5;6;7;8] l
+  OUnit2.assert_equal ~printer:pp_ilist [1;2;3;4;5;6;7;8] l
 *)
 
 let add_seq_front seq q =
@@ -443,7 +443,7 @@ let rec fold : 'a 'b. ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b
 (*$R
   let q = of_iter (Iter.of_list [1;2;3;4]) in
   let n = fold (+) 0 q in
-  OUnit.assert_equal 10 n;
+  OUnit2.assert_equal 10 n;
 *)
 
 let iter f q = to_iter q f
diff --git a/src/data/CCMixtbl.ml b/src/data/CCMixtbl.ml
index c9851355..c3d9ac66 100644
--- a/src/data/CCMixtbl.ml
+++ b/src/data/CCMixtbl.ml
@@ -16,17 +16,17 @@ type 'b injection = {
 (*$R
   let inj_int = create_inj () in
   let tbl = create 10 in
-  OUnit.assert_equal None (get ~inj:inj_int tbl "a");
+  OUnit2.assert_equal None (get ~inj:inj_int tbl "a");
   set ~inj:inj_int tbl "a" 1;
-  OUnit.assert_equal (Some 1) (get ~inj:inj_int tbl "a");
+  OUnit2.assert_equal (Some 1) (get ~inj:inj_int tbl "a");
   let inj_string = create_inj () in
   set ~inj:inj_string tbl "b" "Hello";
-  OUnit.assert_equal (Some "Hello") (get ~inj:inj_string tbl "b");
-  OUnit.assert_equal None (get ~inj:inj_string tbl "a");
-  OUnit.assert_equal (Some 1) (get ~inj:inj_int tbl "a");
+  OUnit2.assert_equal (Some "Hello") (get ~inj:inj_string tbl "b");
+  OUnit2.assert_equal None (get ~inj:inj_string tbl "a");
+  OUnit2.assert_equal (Some 1) (get ~inj:inj_int tbl "a");
   set ~inj:inj_string tbl "a" "Bye";
-  OUnit.assert_equal None (get ~inj:inj_int tbl "a");
-  OUnit.assert_equal (Some "Bye") (get ~inj:inj_string tbl "a");
+  OUnit2.assert_equal None (get ~inj:inj_int tbl "a");
+  OUnit2.assert_equal (Some "Bye") (get ~inj:inj_string tbl "a");
 *)
 
 type 'a t = ('a, unit -> unit) Hashtbl.t
@@ -58,12 +58,12 @@ let length tbl = Hashtbl.length tbl
   let tbl = create 5 in
   set ~inj:inj_int tbl "foo" 1;
   set ~inj:inj_int tbl "bar" 2;
-  OUnit.assert_equal 2 (length tbl);
-  OUnit.assert_equal 2 (find ~inj:inj_int tbl "bar");
+  OUnit2.assert_equal 2 (length tbl);
+  OUnit2.assert_equal 2 (find ~inj:inj_int tbl "bar");
   set ~inj:inj_int tbl "foo" 42;
-  OUnit.assert_equal 2 (length tbl);
+  OUnit2.assert_equal 2 (length tbl);
   remove tbl "bar";
-  OUnit.assert_equal 1 (length tbl);
+  OUnit2.assert_equal 1 (length tbl);
 *)
 
 let clear tbl = Hashtbl.clear tbl
@@ -75,9 +75,9 @@ let clear tbl = Hashtbl.clear tbl
   set ~inj:inj_int tbl "foo" 1;
   set ~inj:inj_int tbl "bar" 2;
   set ~inj:inj_str tbl "baaz" "hello";
-  OUnit.assert_equal 3 (length tbl);
+  OUnit2.assert_equal 3 (length tbl);
   clear tbl;
-  OUnit.assert_equal 0 (length tbl);
+  OUnit2.assert_equal 0 (length tbl);
 *)
 
 let remove tbl x = Hashtbl.remove tbl x
@@ -100,12 +100,12 @@ let mem ~inj tbl x =
   set ~inj:inj_int tbl "foo" 1;
   set ~inj:inj_int tbl "bar" 2;
   set ~inj:inj_str tbl "baaz" "hello";
-  OUnit.assert_bool "mem foo int" (mem ~inj:inj_int tbl "foo");
-  OUnit.assert_bool "mem bar int" (mem ~inj:inj_int tbl "bar");
-  OUnit.assert_bool "not mem baaz int" (not (mem ~inj:inj_int tbl "baaz"));
-  OUnit.assert_bool "not mem foo str" (not (mem ~inj:inj_str tbl "foo"));
-  OUnit.assert_bool "not mem bar str" (not (mem ~inj:inj_str tbl "bar"));
-  OUnit.assert_bool "mem baaz str" (mem ~inj:inj_str tbl "baaz");
+  OUnit2.assert_bool "mem foo int" (mem ~inj:inj_int tbl "foo");
+  OUnit2.assert_bool "mem bar int" (mem ~inj:inj_int tbl "bar");
+  OUnit2.assert_bool "not mem baaz int" (not (mem ~inj:inj_int tbl "baaz"));
+  OUnit2.assert_bool "not mem foo str" (not (mem ~inj:inj_str tbl "foo"));
+  OUnit2.assert_bool "not mem bar str" (not (mem ~inj:inj_str tbl "bar"));
+  OUnit2.assert_bool "mem baaz str" (mem ~inj:inj_str tbl "baaz");
 *)
 
 let find ~inj tbl x =
@@ -136,7 +136,7 @@ let keys_iter tbl yield =
   set ~inj:inj_int tbl "bar" 2;
   set ~inj:inj_str tbl "baaz" "hello";
   let l = keys_iter tbl |> Iter.to_list in
-  OUnit.assert_equal ["baaz"; "bar"; "foo"] (List.sort compare l);
+  OUnit2.assert_equal ["baaz"; "bar"; "foo"] (List.sort compare l);
 *)
 
 let bindings_of ~inj tbl yield =
@@ -164,7 +164,7 @@ let bindings tbl yield =
   set ~inj:inj_str tbl "baaz" "hello";
   set ~inj:inj_str tbl "str" "rts";
   let l_int = bindings_of ~inj:inj_int tbl |> Iter.to_list in
-  OUnit.assert_equal ["bar", 2; "foo", 1] (List.sort compare l_int);
+  OUnit2.assert_equal ["bar", 2; "foo", 1] (List.sort compare l_int);
   let l_str = bindings_of ~inj:inj_str tbl |> Iter.to_list in
-  OUnit.assert_equal ["baaz", "hello"; "str", "rts"] (List.sort compare l_str);
+  OUnit2.assert_equal ["baaz", "hello"; "str", "rts"] (List.sort compare l_str);
 *)
diff --git a/src/data/CCMixtbl.mli b/src/data/CCMixtbl.mli
index 78a1ea13..25fecddc 100644
--- a/src/data/CCMixtbl.mli
+++ b/src/data/CCMixtbl.mli
@@ -11,23 +11,23 @@
 
       let tbl = CCMixtbl.create 10 ;;
 
-      OUnit.assert_equal None (CCMixtbl.get ~inj:inj_int tbl "a");;
+      OUnit2.assert_equal None (CCMixtbl.get ~inj:inj_int tbl "a");;
 
       CCMixtbl.set inj_int tbl "a" 1;;
 
-      OUnit.assert_equal (Some 1) (CCMixtbl.get ~inj:inj_int tbl "a");;
+      OUnit2.assert_equal (Some 1) (CCMixtbl.get ~inj:inj_int tbl "a");;
 
       let inj_string = CCMixtbl.create_inj () ;;
 
       CCMixtbl.set inj_string tbl "b" "Hello";
 
-      OUnit.assert_equal (Some "Hello") (CCMixtbl.get inj_string tbl "b");;
-      OUnit.assert_equal None (CCMixtbl.get inj_string tbl "a");;
-      OUnit.assert_equal (Some 1) (CCMixtbl.get inj_int tbl "a");;
+      OUnit2.assert_equal (Some "Hello") (CCMixtbl.get inj_string tbl "b");;
+      OUnit2.assert_equal None (CCMixtbl.get inj_string tbl "a");;
+      OUnit2.assert_equal (Some 1) (CCMixtbl.get inj_int tbl "a");;
       CCMixtbl.set inj_string tbl "a" "Bye";;
 
-      OUnit.assert_equal None (CCMixtbl.get inj_int tbl "a");;
-      OUnit.assert_equal (Some "Bye") (CCMixtbl.get inj_string tbl "a");;
+      OUnit2.assert_equal None (CCMixtbl.get inj_int tbl "a");;
+      OUnit2.assert_equal (Some "Bye") (CCMixtbl.get inj_string tbl "a");;
     ]}
 
     @since 0.6 *)
diff --git a/src/data/CCPersistentHashtbl.ml b/src/data/CCPersistentHashtbl.ml
index b682b193..f5abee52 100644
--- a/src/data/CCPersistentHashtbl.ml
+++ b/src/data/CCPersistentHashtbl.ml
@@ -224,13 +224,13 @@ module Make(H : HashedType) : S with type key = H.t = struct
 
   (*$R
     let h = H.of_iter my_iter in
-    OUnit.assert_equal "a" (H.find h 1);
-    OUnit.assert_raises Not_found (fun () -> H.find h 5);
+    OUnit2.assert_equal "a" (H.find h 1);
+    OUnit2.assert_raises Not_found (fun () -> H.find h 5);
     let h' = H.replace h 5 "e" in
-    OUnit.assert_equal "a" (H.find h' 1);
-    OUnit.assert_equal "e" (H.find h' 5);
-    OUnit.assert_equal "a" (H.find h 1);
-    OUnit.assert_raises Not_found (fun () -> H.find h 5);
+    OUnit2.assert_equal "a" (H.find h' 1);
+    OUnit2.assert_equal "e" (H.find h' 5);
+    OUnit2.assert_equal "a" (H.find h 1);
+    OUnit2.assert_raises Not_found (fun () -> H.find h 5);
   *)
 
   (*$R
@@ -239,9 +239,9 @@ module Make(H : HashedType) : S with type key = H.t = struct
     let h = H.of_iter seq in
     Iter.iter
       (fun (k,v) ->
-        OUnit.assert_equal ~printer:(fun x -> x) v (H.find h k))
+        OUnit2.assert_equal ~printer:(fun x -> x) v (H.find h k))
       seq;
-    OUnit.assert_raises Not_found (fun () -> H.find h (n+1));
+    OUnit2.assert_raises Not_found (fun () -> H.find h (n+1));
   *)
 
   (*$QR
@@ -271,7 +271,7 @@ module Make(H : HashedType) : S with type key = H.t = struct
     let h = H.of_iter
       Iter.(map (fun i -> i, string_of_int i)
         (0 -- 200)) in
-    OUnit.assert_equal 201 (H.length h);
+    OUnit2.assert_equal 201 (H.length h);
   *)
 
   (*$QR
@@ -371,21 +371,21 @@ module Make(H : HashedType) : S with type key = H.t = struct
 
   (*$R
     let h = H.of_iter my_iter in
-    OUnit.assert_equal "a" (H.find h 1);
-    OUnit.assert_raises Not_found (fun () -> H.find h 5);
+    OUnit2.assert_equal "a" (H.find h 1);
+    OUnit2.assert_raises Not_found (fun () -> H.find h 5);
     let h1 = H.add h 5 "e" in
-    OUnit.assert_equal "a" (H.find h1 1);
-    OUnit.assert_equal "e" (H.find h1 5);
-    OUnit.assert_equal "a" (H.find h 1);
+    OUnit2.assert_equal "a" (H.find h1 1);
+    OUnit2.assert_equal "e" (H.find h1 5);
+    OUnit2.assert_equal "a" (H.find h 1);
     let h2 = H.add h1 5 "ee" in
-    OUnit.assert_equal "ee" (H.find h2 5);
-    OUnit.assert_raises Not_found (fun () -> H.find h 5);
+    OUnit2.assert_equal "ee" (H.find h2 5);
+    OUnit2.assert_raises Not_found (fun () -> H.find h 5);
     let h3 = H.remove h2 1 in
-    OUnit.assert_equal "ee" (H.find h3 5);
-    OUnit.assert_raises Not_found (fun () -> H.find h3 1);
+    OUnit2.assert_equal "ee" (H.find h3 5);
+    OUnit2.assert_raises Not_found (fun () -> H.find h3 1);
     let h4 = H.remove h3 5 in
-    OUnit.assert_equal "e" (H.find h4 5);
-    OUnit.assert_equal "ee" (H.find h3 5);
+    OUnit2.assert_equal "e" (H.find h4 5);
+    OUnit2.assert_equal "ee" (H.find h3 5);
   *)
 
 
@@ -415,14 +415,14 @@ module Make(H : HashedType) : S with type key = H.t = struct
 
   (*$R
     let h = H.of_iter my_iter in
-    OUnit.assert_equal (H.find h 2) "b";
-    OUnit.assert_equal (H.find h 3) "c";
-    OUnit.assert_equal (H.find h 4) "d";
-    OUnit.assert_equal (H.length h) 4;
+    OUnit2.assert_equal (H.find h 2) "b";
+    OUnit2.assert_equal (H.find h 3) "c";
+    OUnit2.assert_equal (H.find h 4) "d";
+    OUnit2.assert_equal (H.length h) 4;
     let h = H.remove h 2 in
-    OUnit.assert_equal (H.find h 3) "c";
-    OUnit.assert_equal (H.length h) 3;
-    OUnit.assert_raises Not_found (fun () -> H.find h 2)
+    OUnit2.assert_equal (H.find h 3) "c";
+    OUnit2.assert_equal (H.length h) 3;
+    OUnit2.assert_raises Not_found (fun () -> H.find h 2)
   *)
 
   (*$R
@@ -430,10 +430,10 @@ module Make(H : HashedType) : S with type key = H.t = struct
     let n = 10000 in
     let seq = Iter.map (fun i -> i, string_of_int i) (0 -- n) in
     let h = H.of_iter seq in
-    OUnit.assert_equal (n+1) (H.length h);
+    OUnit2.assert_equal (n+1) (H.length h);
     let h = Iter.fold (fun h i -> H.remove h i) h (0 -- 500) in
-    OUnit.assert_equal (n-500) (H.length h);
-    OUnit.assert_bool "is_empty" (H.is_empty (H.create 16));
+    OUnit2.assert_equal (n-500) (H.length h);
+    OUnit2.assert_bool "is_empty" (H.is_empty (H.create 16));
   *)
 
   (*$QR
@@ -569,10 +569,10 @@ module Make(H : HashedType) : S with type key = H.t = struct
         | `Both (s1,s2) -> if s1 < s2 then Some s1 else Some s2)
       t1 t2
     in
-    OUnit.assert_equal ~printer:string_of_int 3 (H.length t);
-    OUnit.assert_equal "a" (H.find t 1);
-    OUnit.assert_equal "b1" (H.find t 2);
-    OUnit.assert_equal "c" (H.find t 3);
+    OUnit2.assert_equal ~printer:string_of_int 3 (H.length t);
+    OUnit2.assert_equal "a" (H.find t 1);
+    OUnit2.assert_equal "b1" (H.find t 2);
+    OUnit2.assert_equal "c" (H.find t 3);
   *)
 
   let add_iter init seq =
@@ -611,7 +611,7 @@ module Make(H : HashedType) : S with type key = H.t = struct
   (*$R
     let h = H.of_iter my_iter in
     let l = Iter.to_list (H.to_iter h) in
-    OUnit.assert_equal my_list (List.sort compare l)
+    OUnit2.assert_equal my_list (List.sort compare l)
   *)
 
   let to_iter t =
@@ -620,9 +620,9 @@ module Make(H : HashedType) : S with type key = H.t = struct
 
   (*$R
     let h = H.of_iter my_iter in
-    OUnit.assert_equal "b" (H.find h 2);
-    OUnit.assert_equal "a" (H.find h 1);
-    OUnit.assert_raises Not_found (fun () -> H.find h 42);
+    OUnit2.assert_equal "b" (H.find h 2);
+    OUnit2.assert_equal "a" (H.find h 1);
+    OUnit2.assert_raises Not_found (fun () -> H.find h 42);
   *)
 
   let equal eq t1 t2 =
diff --git a/src/threads/CCPool.ml b/src/threads/CCPool.ml
index 60e8687d..fc138a47 100644
--- a/src/threads/CCPool.ml
+++ b/src/threads/CCPool.ml
@@ -304,7 +304,7 @@ module Make(P : PARAM) = struct
                 1
             )) l in
           let l' = List.map Fut.get l in
-          OUnit.assert_equal n (List.fold_left (+) 0 l');
+          OUnit2.assert_equal n (List.fold_left (+) 0 l');
         )
         [ 10; 300; ]
     *)
@@ -320,7 +320,7 @@ module Make(P : PARAM) = struct
                 1
             )) l in
           let l' = List.map Fut2.get l in
-          OUnit.assert_equal n (List.fold_left (+) 0 l');
+          OUnit2.assert_equal n (List.fold_left (+) 0 l');
         )
         [ 10; 300; ]
     *)
@@ -443,21 +443,21 @@ module Make(P : PARAM) = struct
       let a = Fut.make (fun () -> 1) in
       let b = Fut.return 42 in
       let c = Fut.monoid_product CCPair.make a b in
-      OUnit.assert_equal (1,42) (Fut.get c)
+      OUnit2.assert_equal (1,42) (Fut.get c)
     *)
 
     (*$R
       let a = Fut.make (fun () -> 1) in
       let b = Fut.make (fun () -> 42) in
       let c = Fut.monoid_product CCPair.make a b in
-      OUnit.assert_equal (1,42) (Fut.get c)
+      OUnit2.assert_equal (1,42) (Fut.get c)
     *)
 
     (*$R
       let a = Fut.make (fun () -> 1) in
       let b = Fut.map succ @@ Fut.make (fun () -> 41) in
       let c = Fut.monoid_product CCPair.make a b in
-      OUnit.assert_equal (1,42) (Fut.get c)
+      OUnit2.assert_equal (1,42) (Fut.get c)
     *)
 
     let monoid_product f x y = match x, y with
@@ -582,7 +582,7 @@ module Make(P : PARAM) = struct
         |> Fut.map (List.fold_left (+) 0)
       in
       let expected = List.fold_left (fun acc x -> acc + 10 * x) 0 l in
-      OUnit.assert_equal expected (Fut.get l')
+      OUnit2.assert_equal expected (Fut.get l')
     *)
 
     (*$R
@@ -594,7 +594,7 @@ module Make(P : PARAM) = struct
         |> Fut.map (List.fold_left (+) 0)
       in
       let expected = 100_000 in
-      OUnit.assert_equal expected (Fut.get l')
+      OUnit2.assert_equal expected (Fut.get l')
     *)
 
     (*$R
@@ -605,7 +605,7 @@ module Make(P : PARAM) = struct
         |> Fut.sequence_l
         |> Fut.map (List.fold_left (+) 0)
       in
-      OUnit.assert_raises Exit (fun () -> Fut.get l')
+      OUnit2.assert_raises Exit (fun () -> Fut.get l')
     *)
 
     (*$R
@@ -616,9 +616,9 @@ module Make(P : PARAM) = struct
           (fun x-> Fut.make (fun () -> Thread.yield(); fib (x mod 20)))
         |> Fut.(map_l (fun x->x>|= fun x->x+1))
       in
-      OUnit.assert_bool "not done" (Fut.state l = Waiting);
+      OUnit2.assert_bool "not done" (Fut.state l = Waiting);
       let l' = Fut.get l in
-      OUnit.assert_equal 10_000 (List.length l');
+      OUnit2.assert_equal 10_000 (List.length l');
     *)
 
     (*$R
@@ -630,7 +630,7 @@ module Make(P : PARAM) = struct
         |> Fut2.map (List.fold_left (+) 0)
       in
       let expected = List.fold_left (fun acc x -> acc + 10 * x) 0 l in
-      OUnit.assert_equal expected (Fut2.get l')
+      OUnit2.assert_equal expected (Fut2.get l')
     *)
 
     (*$R
@@ -641,7 +641,7 @@ module Make(P : PARAM) = struct
         |> Fut2.sequence_l
         |> Fut2.map (List.fold_left (+) 0)
       in
-      OUnit.assert_raises Exit (fun () -> Fut2.get l')
+      OUnit2.assert_raises Exit (fun () -> Fut2.get l')
     *)
 
     (*$R
@@ -652,9 +652,9 @@ module Make(P : PARAM) = struct
           (fun x-> Fut2.make (fun () -> Thread.yield(); fib (x mod 20)))
         |> Fut2.(map_l (fun x->x>|= fun x->x+1))
       in
-      OUnit.assert_bool "not done" (Fut2.state l = Waiting);
+      OUnit2.assert_bool "not done" (Fut2.state l = Waiting);
       let l' = Fut2.get l in
-      OUnit.assert_equal 10_000 (List.length l');
+      OUnit2.assert_equal 10_000 (List.length l');
     *)
 
 
@@ -690,7 +690,7 @@ module Make(P : PARAM) = struct
       in
       List.iter Fut.get l;
       let stop = Unix.gettimeofday () in
-      OUnit.assert_bool "some_parallelism" (stop -. start < float_of_int n *. pause);
+      OUnit2.assert_bool "some_parallelism" (stop -. start < float_of_int n *. pause);
     *)
 
     (*$R
@@ -701,7 +701,7 @@ module Make(P : PARAM) = struct
       in
       List.iter Fut2.get l;
       let stop = Unix.gettimeofday () in
-      OUnit.assert_bool "some_parallelism" (stop -. start < float_of_int n *. pause);
+      OUnit2.assert_bool "some_parallelism" (stop -. start < float_of_int n *. pause);
     *)
 
     module Infix = struct
diff --git a/src/threads/CCTimer.ml b/src/threads/CCTimer.ml
index b3c6e75d..97783d04 100644
--- a/src/threads/CCTimer.ml
+++ b/src/threads/CCTimer.ml
@@ -168,9 +168,9 @@ let every ?delay timer d ~f =
         raise ExitEvery
       ));
   CCSemaphore.acquire 1 sem; (* wait *)
-  OUnit.assert_equal ~printer:CCInt.to_string 6 (CCLock.get res);
-  OUnit.assert_bool "delay >= 0.5" (!stop -. start >= 0.49999);
-  OUnit.assert_bool "delay < 2." (!stop -. start < 2.);
+  OUnit2.assert_equal ~printer:CCInt.to_string 6 (CCLock.get res);
+  OUnit2.assert_bool "delay >= 0.5" (!stop -. start >= 0.49999);
+  OUnit2.assert_bool "delay < 2." (!stop -. start < 2.);
 *)
 (* NOTE: could be tighter bounds, but travis' mac OS seems to be dog slow. *)
 
@@ -201,5 +201,5 @@ let stop timer =
   after timer 0.1
     ~f:(fun () -> CCLock.update n (fun x -> x * 4));
   Thread.delay 0.6 ;
-  OUnit.assert_equal ~printer:Q.Print.int 6 (CCLock.get res);
+  OUnit2.assert_equal ~printer:Q.Print.int 6 (CCLock.get res);
 *)