bpo-42843: Keep Sphinx 1.8 and Sphinx 2 compatibility (GH-24282)

diff --git a/Doc/library/xml.dom.minidom.rst b/Doc/library/xml.dom.minidom.rst
index e1cc967..bf72c46 100644
--- a/Doc/library/xml.dom.minidom.rst
+++ b/Doc/library/xml.dom.minidom.rst
@@ -174,7 +174,7 @@
       The :meth:`toxml` method now preserves the attribute order specified
       by the user.
 
-.. method:: Node.toprettyxml(indent="\t", newl="\n", encoding=None, \
+.. method:: Node.toprettyxml(indent="\\t", newl="\\n", encoding=None, \
                              standalone=None)
 
    Return a pretty-printed version of the document. *indent* specifies the