diff --git a/flap/src/hopix/hopixInterpreter.ml b/flap/src/hopix/hopixInterpreter.ml
index a53799f..e77f648 100644
--- a/flap/src/hopix/hopixInterpreter.ml
+++ b/flap/src/hopix/hopixInterpreter.ml
@@ -460,9 +460,7 @@ and case_value expr branches environment memory =
   in
   (* On fait le match avec ce qu'on a comme info *)
   match branches' with
-  | [] ->
-    (* TODO *)
-    error [] "error"
+  | [] -> error [ expr.position ] "erreur"
   | _ as env -> List.hd env
 
 and for_value id expr1 expr2 expr3 environment memory =