diff --git a/impression/wrapper_canon.ml b/impression/wrapper_canon.ml
index 69177d35..b7610dd1 100644
--- a/impression/wrapper_canon.ml
+++ b/impression/wrapper_canon.ml
@@ -46,7 +46,7 @@ let _MediaSize () = string_of_int (match String.lowercase (!papier) with
   | "c5 env" -> 9
   | "b5 env" -> 10
   | "dl env" -> 11
-  | _ -> raise (Arg.Bad ("%s wrong papersize" % !papier))
+  | _ -> raise (Arg.Bad ("%s wrong papersize" % !papier)))
 
 let papertype = ref "Ordinaire"
 let _MediaType () = List.assoc !papertype& List.map (fun (x,y) -> y,x)