diff --git a/Objects/abstract.c b/Objects/abstract.c
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1681,7 +1681,7 @@
         Py_INCREF(v);
         return v;
     }
-    if (PyList_Check(v))
+    if (PyList_CheckExact(v))
         return PyList_AsTuple(v);
 
     /* Get iterator. */