diff --git a/trackintel/io/file.py b/trackintel/io/file.py
index d109ab93..9e9743a2 100644
--- a/trackintel/io/file.py
+++ b/trackintel/io/file.py
@@ -556,10 +556,7 @@ def read_tours_csv(*args, columns=None, index_col=None, tz=None, **kwargs):
     >>> trackintel.read_tours_csv('data.csv', columns={'uuid':'user_id'})
     """
     columns = {} if columns is None else columns
-    if "converters" not in kwargs:
-        kwargs["converters"] = {"trips": ast.literal_eval}
-    elif "trips" not in kwargs["converters"]:
-        kwargs["converters"]["trips"] = ast.literal_eval
+    kwargs.setdefault("converters", {}).setdefault("trips", ast.literal_eval)
     tours = pd.read_csv(*args, index_col=index_col, **kwargs)
     tours.rename(columns=columns, inplace=True)