More Py_ssize_t format characters.
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 728c971..bdbda22 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -245,7 +245,7 @@
 	int len;
 
 	CHECK_VALID(NULL);
-	if (!PyArg_ParseTuple (args, "s#|l:find", &needle, &len, &start)) {
+	if (!PyArg_ParseTuple (args, "s#|n:find", &needle, &len, &start)) {
 		return NULL;
 	} else {
 		char *p;