diff --git a/src/nextroute/options.py b/src/nextroute/options.py
index 10df971..b565416 100644
--- a/src/nextroute/options.py
+++ b/src/nextroute/options.py
@@ -155,7 +155,7 @@ def to_args(self) -> List[str]:
             if value == default_value:
                 continue
 
-            key = f"-{key.replace("_", ".").lower()}"
+            key = f"-{key.replace('_', '.').lower()}"
 
             str_value = json.dumps(value)
             if key in _DURATIONS_ARGS: