diff --git a/src/data/CCDeque.ml b/src/data/CCDeque.ml
index 48d05e4d..47e46b43 100644
--- a/src/data/CCDeque.ml
+++ b/src/data/CCDeque.ml
@@ -134,3 +134,16 @@ let copy d =
   let d' = create () in
   iter (fun x -> push_back d' x) d;
   d'
+
+type 'a printer = Format.formatter -> 'a -> unit
+
+let print pp_x out d =
+  let first = ref true in
+  Format.fprintf out "@[<hov2>deque {";
+  iter
+    (fun x ->
+      if !first then first:= false else Format.fprintf out ";@ ";
+      pp_x out x
+    ) d;
+  Format.fprintf out "}@]"
+    
diff --git a/src/data/CCDeque.mli b/src/data/CCDeque.mli
index 046e7148..eaed962d 100644
--- a/src/data/CCDeque.mli
+++ b/src/data/CCDeque.mli
@@ -66,3 +66,8 @@ val to_seq : 'a t -> 'a sequence
 
 val copy : 'a t -> 'a t
   (** Fresh copy *)
+
+type 'a printer = Format.formatter -> 'a -> unit
+
+val print : 'a printer -> 'a t printer
+  (** @since NEXT_RELEASE *)