diff --git a/simple-utils/x_list.ml b/simple-utils/x_list.ml
index 5462167e2..9037b0e9e 100644
--- a/simple-utils/x_list.ml
+++ b/simple-utils/x_list.ml
@@ -2,7 +2,7 @@ include List
 
 let rec remove n = function
   | [] -> raise (Failure "List.remove")
-  | hd :: tl when n = 0 -> tl
+  | _  :: tl when n = 0 -> tl
   | hd :: tl -> hd :: remove (n - 1) tl