diff --git a/Doc/c-api/sequence.rst b/Doc/c-api/sequence.rst
index cf1e142..5960db9 100644
--- a/Doc/c-api/sequence.rst
+++ b/Doc/c-api/sequence.rst
@@ -107,8 +107,9 @@ Sequence Protocol
 
 .. c:function:: PyObject* PySequence_List(PyObject *o)
 
-   Return a list object with the same contents as the arbitrary sequence *o*.  The
-   returned list is guaranteed to be new.
+   Return a list object with the same contents as the sequence or iterable *o*,
+   or *NULL* on failure.  The returned list is guaranteed to be new.  This is
+   equivalent to the Python expression ``list(o)``.
 
 
 .. c:function:: PyObject* PySequence_Tuple(PyObject *o)