diff --git a/Makefile b/Makefile
index 600c94ca..d874f3df 100644
--- a/Makefile
+++ b/Makefile
@@ -30,9 +30,9 @@ update_next_tag:
 	sed -i "s/NEXT_VERSION/$(VERSION)/g" $(wildcard src/**/*.ml) $(wildcard src/**/*.mli)
 	sed -i "s/NEXT_RELEASE/$(VERSION)/g" $(wildcard src/**/*.ml) $(wildcard src/**/*.mli)
 
-WATCH?=@all
+WATCH?="@src/all @tests/runtest"
 watch:
-	@dune build $(WATCH) -w
+	@dune build "$(WATCH)" -w
 
 reindent:
 	@which ocp-indent || ( echo "require ocp-indent" ; exit 1 )
diff --git a/src/data/CCHet.ml b/src/data/CCHet.ml
index 053619a3..1f544db7 100644
--- a/src/data/CCHet.ml
+++ b/src/data/CCHet.ml
@@ -85,6 +85,8 @@ module Tbl = struct
   let to_list t = M.fold (fun _ p l -> pair_of_e_pair p :: l) t []
   let add_list t l = List.iter (add_pair_ t) l
   let add_iter t seq = seq (add_pair_ t)
+  let clear t = M.clear t
+  let reset t = M.reset t
 
   let of_list l =
     let t = create () in
diff --git a/src/data/CCHet.mli b/src/data/CCHet.mli
index 14f95b67..70b35354 100644
--- a/src/data/CCHet.mli
+++ b/src/data/CCHet.mli
@@ -1,5 +1,3 @@
-(* This file is free software, part of containers. See file "license" for more details. *)
-
 (** Associative containers with Heterogeneous Values
 
     This is similar to {!CCMixtbl}, but the injection is directly used as
@@ -7,13 +5,21 @@
 
     @since 0.17 *)
 
+(* This file is free software, part of containers. See file "license" for more details. *)
+
 type 'a iter = ('a -> unit) -> unit
 type 'a gen = unit -> 'a option
 
+(** Keys with a type witness. *)
 module Key : sig
   type 'a t
+  (** A key of type ['a t] is used to access the portion of the
+      map or table that associates keys of type ['a] to values. *)
 
   val create : unit -> 'a t
+  (** Make a new key. This is generative, so calling [create ()] twice with the
+      same return type will produce incompatible keys that cannot see each
+      other's bindings. *)
 
   val equal : 'a t -> 'a t -> bool
   (** Compare two keys that have compatible types. *)
@@ -32,6 +38,14 @@ module Tbl : sig
   val length : t -> int
   val find : t -> 'a Key.t -> 'a option
 
+  val clear : t -> unit
+  (** clear the table (like {!Hashtbl.clear})
+      @since NEXT_RELEASE *)
+
+  val reset : t -> unit
+  (** reset the table (like {!Hashtbl.reset})
+      @since NEXT_RELEASE *)
+
   val find_exn : t -> 'a Key.t -> 'a
   (** @raise Not_found if the key is not in the table. *)