diff --git a/omv_backup.py b/omv_backup.py
index a881f86..7f15e5f 100755
--- a/omv_backup.py
+++ b/omv_backup.py
@@ -650,7 +650,7 @@ if _BACKUP:
                     if _EXECUTE:
                         status, output = subprocess.getstatusoutput(cmnd)
                         for f in output.splitlines():
-                            dir_path = "{BACKUP_ROOT}/{f}"
+                            dir_path = f"{BACKUP_ROOT}/{f}"
                             logging.info(f"removing {dir_path}")
                             shutil.rmtree(dir_path)