diff --git a/src/anthropic/_response.py b/src/anthropic/_response.py
index 32104410..830bee51 100644
--- a/src/anthropic/_response.py
+++ b/src/anthropic/_response.py
@@ -226,7 +226,9 @@ def _parse(self, *, to: type[_T] | None = None) -> R | _T:
         if origin == APIResponse:
             raise RuntimeError("Unexpected state - cast_to is `APIResponse`")
 
-        if inspect.isclass(origin) and issubclass(origin, httpx.Response):
+        if inspect.isclass(
+            origin  # pyright: ignore[reportUnknownArgumentType]
+        ) and issubclass(origin, httpx.Response):
             # Because of the invariance of our ResponseT TypeVar, users can subclass httpx.Response
             # and pass that class to our request functions. We cannot change the variance to be either
             # covariant or contravariant as that makes our usage of ResponseT illegal. We could construct