diff --git a/src/core/CCVector.ml b/src/core/CCVector.ml
index 5180758e..acf8d8ca 100644
--- a/src/core/CCVector.ml
+++ b/src/core/CCVector.ml
@@ -533,15 +533,26 @@ let flat_map f v =
   iter (fun x -> iter (push v') (f x)) v;
   v'
 
-let flat_map' f v =
+let flat_map_seq f v =
   let v' = create () in
   iter
     (fun x ->
       let seq = f x in
-      seq (fun y -> push v' y)
+      append_seq v' seq;
     ) v;
   v'
 
+let flat_map_list f v =
+  let v' = create () in
+  iter
+    (fun x ->
+      let l = f x in
+      append_list v' l;
+    ) v;
+  v'
+
+let flat_map' = flat_map_seq
+
 let (>>=) x f = flat_map f x
 
 let (>|=) x f = map f x
diff --git a/src/core/CCVector.mli b/src/core/CCVector.mli
index 17d21bfd..deec25fd 100644
--- a/src/core/CCVector.mli
+++ b/src/core/CCVector.mli
@@ -190,8 +190,19 @@ val filter_map : ('a -> 'b option) -> ('a,_) t -> ('b, 'mut) t
 val flat_map : ('a -> ('b,_) t) -> ('a,_) t -> ('b, 'mut) t
 (** Map each element to a sub-vector *)
 
+val flat_map_seq : ('a -> 'b sequence) -> ('a,_) t -> ('b, 'mut) t
+(** Like {!flat_map}, but using {!sequence} for
+    intermediate collections.
+    @since NEXT_RELEASE *)
+
+val flat_map_list : ('a -> 'b list) -> ('a,_) t -> ('b, 'mut) t
+(** Like {!flat_map}, but using {!list} for
+    intermediate collections.
+    @since NEXT_RELEASE *)
+
 val flat_map' : ('a -> 'b sequence) -> ('a,_) t -> ('b, 'mut) t
-(** Like {!flat_map}, but using {!sequence} for intermediate collections *)
+(** Alias to {!flat_map_seq}
+   @deprecated since NEXT_RELEASE , use {!flat_map_seq} *)
 
 val (>>=) : ('a,_) t -> ('a -> ('b,_) t) -> ('b, 'mut) t
 (** Infix version of {!flat_map} *)