diff --git a/ohsome/clients.py b/ohsome/clients.py
index 0751a33..588e337 100644
--- a/ohsome/clients.py
+++ b/ohsome/clients.py
@@ -55,7 +55,7 @@ def __init__(
         RetryError by the underlying library.
         """
         self.log = log
-        self.log_dir = Path(log_dir)
+        self.log_dir = Path(log_dir or DEFAULT_LOG_DIR)
         if self.log:
             self.log_dir.mkdir(parents=True, exist_ok=True)
         if base_api_url is not None: