diff --git a/libs/lospecs/lospecs_test.ml b/libs/lospecs/lospecs_test.ml
index 0e223398bc..2f10c435fa 100644
--- a/libs/lospecs/lospecs_test.ml
+++ b/libs/lospecs/lospecs_test.ml
@@ -3,8 +3,7 @@ open Lospecs
 
 (* -------------------------------------------------------------------- *)
 let _ =
-  Io.parse IO.stdin
- 
+    Format.printf "%a@." Ptree.pp_program (Io.parse IO.stdin)
 
 (* -------------------------------------------------------------------- *)
 module List : sig
diff --git a/libs/lospecs/ptree.ml b/libs/lospecs/ptree.ml
index e452d63aa4..a1e10f8e56 100644
--- a/libs/lospecs/ptree.ml
+++ b/libs/lospecs/ptree.ml
@@ -76,4 +76,4 @@ type pprogram =
   pdef list
 
 let pp_program (fmt: Format.formatter) (prog: pprogram) = 
-    Format.pp_print_list ~pp_sep:(fun out () -> Format.fprintf out "@.") pp_def fmt prog
+    Format.pp_print_list ~pp_sep:(fun out () -> Format.fprintf out "@.@.") pp_def fmt prog