diff --git a/src/core/CCInt.ml b/src/core/CCInt.ml
index 1d64460b..dd0ae137 100644
--- a/src/core/CCInt.ml
+++ b/src/core/CCInt.ml
@@ -71,10 +71,7 @@ let range' i j yield =
   [5;4;3]     (range' 5 2 |> Iter.to_list)
 *)
 
-let sign i =
-  if i < 0 then -1
-  else if i>0 then 1
-  else 0
+let sign i = compare i 0
 
 let neg i = -i
 
diff --git a/src/core/CCInt.mli b/src/core/CCInt.mli
index 8cef2434..44ba1a61 100644
--- a/src/core/CCInt.mli
+++ b/src/core/CCInt.mli
@@ -68,7 +68,8 @@ val hash : t -> int
 (** [hash x] computes the hash of [x]. *)
 
 val sign : t -> int
-(** [sign x] is one of [-1, 0, 1]. *)
+(** [sign x] return [0] if [x = 0], [-1] if [x < 0] and [1] if [x > 0].
+    Same as [compare x 0].*)
 
 val neg : t -> t
 (** [neg x] is [- x].