diff --git a/src/bigarray/CCBigstring.ml b/src/bigarray/CCBigstring.ml
index efa37a74..2e0cee84 100644
--- a/src/bigarray/CCBigstring.ml
+++ b/src/bigarray/CCBigstring.ml
@@ -48,6 +48,7 @@ let get = B.get
 let set = B.set
 
 let size = B.dim
+let length = B.dim
 
 let sub = B.sub
 
diff --git a/src/bigarray/CCBigstring.mli b/src/bigarray/CCBigstring.mli
index 6f0582e1..33970486 100644
--- a/src/bigarray/CCBigstring.mli
+++ b/src/bigarray/CCBigstring.mli
@@ -45,6 +45,10 @@ val fill : t -> char -> unit
 val size : t -> int
 (** Number of bytes *)
 
+val length : t -> int
+(** Alias for [size].
+    @since NEXT_RELEASE *)
+
 val get : t -> int -> char
 
 val set : t -> int -> char -> unit