diff --git a/Include/modsupport.h b/Include/modsupport.h
index 63f866e4849..c356f03e503 100644
--- a/Include/modsupport.h
+++ b/Include/modsupport.h
@@ -25,7 +25,7 @@ PyAPI_FUNC(int) PyArg_Parse(PyObject *, const char *, ...);
 PyAPI_FUNC(int) PyArg_ParseTuple(PyObject *, const char *, ...);
 PyAPI_FUNC(int) PyArg_ParseTupleAndKeywords(PyObject *, PyObject *,
                                                   const char *, char **, ...);
-PyAPI_FUNC(int) PyArg_UnpackTuple(PyObject *, const char *, int, int, ...);
+PyAPI_FUNC(int) PyArg_UnpackTuple(PyObject *, const char *, Py_ssize_t, Py_ssize_t, ...);
 PyAPI_FUNC(PyObject *) Py_BuildValue(const char *, ...);
 PyAPI_FUNC(int) _PyArg_NoKeywords(const char *funcname, PyObject *kw);
 
diff --git a/Python/getargs.c b/Python/getargs.c
index 2af9d885478..e14a07b2269 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -1662,9 +1662,9 @@ skipitem(const char **p_format, va_list *p_va, int flags)
 
 
 int
-PyArg_UnpackTuple(PyObject *args, const char *name, int min, int max, ...)
+PyArg_UnpackTuple(PyObject *args, const char *name, Py_ssize_t min, Py_ssize_t max, ...)
 {
-	int i, l;
+	Py_ssize_t i, l;
 	PyObject **o;
 	va_list vargs;