diff --git a/src/verification.ml b/src/verification.ml
index 836ff1bcb8c628832d6ed9732a2b28518451ac92..85e7b263d5d8a0439d1f7046f8a9f0b8810145d1 100644
--- a/src/verification.ml
+++ b/src/verification.ml
@@ -75,9 +75,15 @@ let answer_saver limit config env config_prover dataset_csv task =
     | Some filename -> filename
   in
   let answer = SAVer.call limit config env config_prover ~dataset task in
-  let prover_answer = answer.prover_answer in
-  let additional_info = Fmt.str "(%d/%d)" answer.nb_proved answer.nb_total in
-  (prover_answer, Some additional_info)
+  match answer.prover_answer with
+  | Call_provers.Unknown "" ->
+    let additional_info = Fmt.str "%d/%d" answer.nb_proved answer.nb_total in
+    (Call_provers.Unknown additional_info, None)
+  | Call_provers.Unknown _ ->
+    assert false (* By construction of SAVer's Unknown answer. *)
+  | prover_answer ->
+    let additional_info = Fmt.str "(%d/%d)" answer.nb_proved answer.nb_total in
+    (prover_answer, Some additional_info)
 
 let answer_generic limit config prover config_prover driver task =
   let task_prepared = Driver.prepare_task driver task in
diff --git a/tests/simple_ovo.t b/tests/simple_ovo.t
index 120aab2d099ffa527f9d8aae7425911ec5eb3855..50150161a62f90f67fc64a2b12210acf4eb1c575 100644
--- a/tests/simple_ovo.t
+++ b/tests/simple_ovo.t
@@ -39,4 +39,4 @@ Test verify
   > EOF
   [caisar] Goal G: Valid (2/2)
   [caisar] Goal H: Invalid (1/2)
-  [caisar] Goal I: Unknown () (0/2)
+  [caisar] Goal I: Unknown (0/2)