diff --git a/src/plugins/wp/Stats.ml b/src/plugins/wp/Stats.ml
index 662b145ba0b734d61780820c951675c7db590c91..3732555a5f7497e62e251ab8467721a816ee256f 100644
--- a/src/plugins/wp/Stats.ml
+++ b/src/plugins/wp/Stats.ml
@@ -187,6 +187,7 @@ let pretty fmt s =
 
 let to_json_p (p,r) : Json.t = `Assoc [
     "prover", `String (VCS.name_of_prover p) ;
+    "hprover", `String (VCS.title_of_prover p) ;
     "time", `Float r.time ;
     "htime", `String (Pretty_utils.to_string Rformat.pp_time r.time) ;
     "success", `Int r.success ;
diff --git a/src/plugins/wp/Why3Provers.ml b/src/plugins/wp/Why3Provers.ml
index 07645004d587aa7a93c6f4fa1f722b17d2029043..167dc3e1370b6261b1861de7846aaf73e0402c48 100644
--- a/src/plugins/wp/Why3Provers.ml
+++ b/src/plugins/wp/Why3Provers.ml
@@ -93,7 +93,7 @@ let print_wp s =
   let prv = String.split_on_char ',' name in
   String.concat ":" prv
 
-let title p = Format.asprintf "%a" Why3.Whyconf.print_prover p
+let title p = Pretty_utils.to_string Why3.Whyconf.print_prover p
 let name p = p.Why3.Whyconf.prover_name
 let compare = Why3.Whyconf.Prover.compare
 let is_mainstream p = p.Why3.Whyconf.prover_altern = ""