diff --git a/src/anthropic/_base_client.py b/src/anthropic/_base_client.py
index 9423bcd4..05efd205 100644
--- a/src/anthropic/_base_client.py
+++ b/src/anthropic/_base_client.py
@@ -768,6 +768,9 @@ def __init__(self, **kwargs: Any) -> None:
 
 class SyncHttpxClientWrapper(DefaultHttpxClient):
     def __del__(self) -> None:
+        if self.is_closed:
+            return
+
         try:
             self.close()
         except Exception:
@@ -1350,6 +1353,9 @@ def __init__(self, **kwargs: Any) -> None:
 
 class AsyncHttpxClientWrapper(DefaultAsyncHttpxClient):
     def __del__(self) -> None:
+        if self.is_closed:
+            return
+
         try:
             # TODO(someday): support non asyncio runtimes here
             asyncio.get_running_loop().create_task(self.aclose())