diff --git a/Include/abstract.h b/Include/abstract.h
index 3491724e318..a870f69c928 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -753,7 +753,8 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
 	 expression: o.count(value).
        */
 
-     int PySequence_In Py_PROTO((PyObject *o, PyObject *value));
+     int PySequence_Contains Py_PROTO((PyObject *o, PyObject *value));
+     #define PySequence_In PySequence_Contains
 
        /*
 	 Determine if o contains value.  If an item in o is equal to