diff --git a/requests_util/__init__.py b/requests_util/__init__.py
index 330e175..a4a39ab 100644
--- a/requests_util/__init__.py
+++ b/requests_util/__init__.py
@@ -54,13 +54,14 @@ def initialize_session(extra_cache_args: dict | None = None) -> requests.Session
         home = pathlib.Path(os.environ['HOME'])
         cache_path = home / CACHE_PATH_FROM_HOME
         cache_path.mkdir(parents=True, exist_ok=True)
-        extra_cache_args = extra_cache_args or {}
+        extra_cache_args = dict(extra_cache_args or {})
+        extra_cache_args.setdefault('expire_after', datetime.timedelta(days=1))
+        extra_cache_args.setdefault('stale_if_error', True)
+        extra_cache_args.setdefault('cache_control', False)
+        extra_cache_args.setdefault('urls_expire_after', {})
+
         session = requests_cache.CachedSession(
             cache_path,
-            expire_after=datetime.timedelta(days=1),
-            stale_if_error=True,
-            cache_control=False,
-            urls_expire_after={},
             **extra_cache_args,
         )
     else: