diff --git a/tools/align_dmz_from_ayoub.py b/tools/align_dmz_from_ayoub.py
index e93ced6..26f2734 100644
--- a/tools/align_dmz_from_ayoub.py
+++ b/tools/align_dmz_from_ayoub.py
@@ -37,7 +37,8 @@ def is_dmz_value(v):
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument("xlsx_path")
-    parser.add_argument("--sheet", default="Serveurs patchables 2026")
+    parser.add_argument("--sheet", default=None,
+                        help="Sheet a utiliser (auto: Histo-2025 ou Serveurs patchables 2026)")
     parser.add_argument("--dry-run", action="store_true")
     args = parser.parse_args()
 
@@ -66,24 +67,28 @@ def main():
             print(f"[INFO] Zone DMZ creee (id={dmz_id})")
 
     wb = openpyxl.load_workbook(args.xlsx_path, data_only=True)
-    if args.sheet not in wb.sheetnames:
-        print(f"[ERR] Sheet '{args.sheet}' introuvable. Sheets: {wb.sheetnames}")
+
+    # Auto-detection sheet si pas specifie
+    sheet_name = args.sheet
+    if not sheet_name:
+        for candidate in ("Histo-2025", "Serveurs patchables 2026", "Histo_2025"):
+            if candidate in wb.sheetnames:
+                sheet_name = candidate
+                break
+    if not sheet_name or sheet_name not in wb.sheetnames:
+        print(f"[ERR] Sheet introuvable. Sheets disponibles: {wb.sheetnames}")
         return
-    ws = wb[args.sheet]
+    ws = wb[sheet_name]
+    print(f"[INFO] Sheet utilisee: {sheet_name}")
 
     header = [str(c.value).strip() if c.value else "" for c in ws[1]]
-    try:
-        idx_host = header.index("Asset Name")
-    except ValueError:
-        try:
-            idx_host = header.index("Hostname")
-        except ValueError:
-            print("[ERR] Colonne Asset Name/Hostname introuvable")
-            return
-    try:
-        idx_dmz = header.index("DMZ")
-    except ValueError:
-        print("[ERR] Colonne DMZ introuvable")
+    idx_host = next((i for i,h in enumerate(header) if h in ("Asset Name", "Hostname", "Nom")), -1)
+    idx_dmz = next((i for i,h in enumerate(header) if h == "DMZ"), -1)
+    if idx_host == -1:
+        print(f"[ERR] Colonne Asset Name/Hostname/Nom introuvable. Headers: {header[:10]}")
+        return
+    if idx_dmz == -1:
+        print(f"[ERR] Colonne DMZ introuvable. Headers: {header}")
         return
     print(f"[INFO] idx_host={idx_host} idx_dmz={idx_dmz}")