diff --git a/backend/destinations.py b/backend/destinations.py
index 008d547..378e5d4 100644
--- a/backend/destinations.py
+++ b/backend/destinations.py
@@ -163,14 +163,43 @@ def recuperer_booth_password() -> dict:
 
 
 def detecter_usb() -> list[str]:
-    """Detecte les cles USB montees."""
-    chemins_possibles = [Path("/media"), Path("/mnt")]
+    """Detecte les cles USB montees (cherche dans /media, /mnt et /media/<user>/)."""
     usb_trouvees = []
-    for racine in chemins_possibles:
-        if racine.exists():
-            for sous_dossier in racine.iterdir():
-                if sous_dossier.is_mount() or (sous_dossier.is_dir() and any(sous_dossier.iterdir())):
-                    usb_trouvees.append(str(sous_dossier))
+    candidats = []
+
+    for racine in [Path("/media"), Path("/mnt")]:
+        if not racine.exists():
+            continue
+        try:
+            for niveau1 in racine.iterdir():
+                if not niveau1.is_dir():
+                    continue
+                if niveau1.is_mount():
+                    candidats.append(niveau1)
+                else:
+                    # /media/<user>/ → descendre encore (udiskie)
+                    try:
+                        for niveau2 in niveau1.iterdir():
+                            if niveau2.is_dir() and niveau2.is_mount():
+                                candidats.append(niveau2)
+                    except PermissionError:
+                        pass
+        except PermissionError:
+            pass
+
+    for chemin in candidats:
+        # Exclure les partitions système
+        try:
+            result = __import__("subprocess").run(
+                ["findmnt", "-no", "FSTYPE", str(chemin)],
+                capture_output=True, text=True, timeout=3
+            )
+            fstype = result.stdout.strip()
+            if fstype in ("vfat", "exfat", "ntfs", "ext4", "ext3", "hfsplus"):
+                usb_trouvees.append(str(chemin))
+        except Exception:
+            usb_trouvees.append(str(chemin))
+
     return usb_trouvees