diff --git a/git_updater.py b/git_updater.py
index 3e27b04..84f34f3 100644
--- a/git_updater.py
+++ b/git_updater.py
@@ -468,9 +468,21 @@ class App(tk.Tk):
         self.repo_results = []
 
         log.info(f"=== Demarrage Git Update Checker v{VERSION} ===")
+        self._cleanup_old_exe()
         self._build_ui()
         self.after(100, self._check_self_update_then_repos)
 
+    def _cleanup_old_exe(self):
+        """Supprime l'ancien exe .old restant d'une mise a jour precedente."""
+        if getattr(sys, "frozen", False):
+            old_path = Path(sys.executable).with_suffix(".exe.old")
+            if old_path.exists():
+                try:
+                    old_path.unlink()
+                    log.info(f"Nettoyage: {old_path.name} supprime")
+                except OSError:
+                    log.warning(f"Nettoyage: impossible de supprimer {old_path.name}")
+
     def _build_ui(self):
         style = ttk.Style(self)
         style.theme_use("clam")
diff --git a/version.txt b/version.txt
index 2eb3c4f..4b9fcbe 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-0.5
+0.5.1