diff --git a/app/scodoc/sco_trombino.py b/app/scodoc/sco_trombino.py
index 84af342639..b5bfb6b527 100644
--- a/app/scodoc/sco_trombino.py
+++ b/app/scodoc/sco_trombino.py
@@ -229,7 +229,7 @@ def _trombino_zip(groups_infos):
         if code_nip:
             filename = code_nip + ".jpg"
         else:
-            filename = t["nom"] + "_" + t["prenom"] + "_" + t["etudid"] + ".jpg"
+            filename = f'{t["nom"]}_{t["prenom"]}_{t["etudid"]}.jpg'
         Z.writestr(filename, img)
     Z.close()
     size = data.tell()