diff --git a/core/CCOpt.ml b/core/CCOpt.ml
index 07be2451..a1dd5395 100644
--- a/core/CCOpt.ml
+++ b/core/CCOpt.ml
@@ -110,6 +110,8 @@ let sequence_l l =
   sequence_l [] = Some []
 *)
 
+let guard f x = try Some (f x) with Not_found -> None
+
 let to_list o = match o with
   | None -> []
   | Some x -> [x]
diff --git a/core/CCOpt.mli b/core/CCOpt.mli
index 2c0e1d4f..e067a097 100644
--- a/core/CCOpt.mli
+++ b/core/CCOpt.mli
@@ -65,6 +65,14 @@ val get_exn : 'a t -> 'a
     @raise Invalid_argument if the option is [None] *)
 
 val sequence_l : 'a t list -> 'a list t
+(** [sequence_l [x1; x2; ...; xn]] returns [Some [y1;y2;...;yn]] if
+    every [xi] is [Some yi]. Otherwise, if the list contains at least
+    one [None], the result is [None]. *)
+
+val guard : ('a -> 'b) -> 'a -> 'b option
+(** [guard f x] calls [f x] and returns [Some y] if [f x = y]. If [f x] raises
+    any exception, the result is [None]. This can be useful to wrap functions
+    such as [Map.S.find]. *)
 
 (** {2 Applicative} *)