diff --git a/src/X86.ml b/src/X86.ml
index b69c360c0..992f5f852 100644
--- a/src/X86.ml
+++ b/src/X86.ml
@@ -389,7 +389,7 @@ module M = Map.Make (String)
 
 (* Environment implementation *)
 class env =
-  let chars          = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNJPQRSTUVWXYZ" in
+  let chars          = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" in
   let make_assoc l i = List.combine l (List.init (List.length l) (fun x -> x + i)) in
   let rec assoc  x   = function [] -> raise Not_found | l :: ls -> try List.assoc x l with Not_found -> assoc x ls in
   object (self)