diff --git a/src/if_py_both.h b/src/if_py_both.h
index 1d99909..f5617ac 100644
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -1139,7 +1139,7 @@
 
     for (i = 0; i < n; ++i)
     {
-	PyObject	*item = ListItem(self, i);
+	PyObject	*item = ListItem(self, first + i);
 	if (item == NULL)
 	{
 	    Py_DECREF(list);