diff --git a/app/models/procedure.rb b/app/models/procedure.rb
index 16db00fda..0af87e5a9 100644
--- a/app/models/procedure.rb
+++ b/app/models/procedure.rb
@@ -693,7 +693,7 @@ class Procedure < ApplicationRecord
       dossiers_sample = dossiers.termine.limit(100)
       total_size = Champ
         .includes(piece_justificative_file_attachment: :blob)
-        .where(type: "Champs::PieceJustificativeChamp", dossier: dossiers_sample)
+        .where(type: Champs::PieceJustificativeChamp.to_s, dossier: dossiers_sample)
         .sum('active_storage_blobs.byte_size')
 
       total_size / dossiers_sample.length