diff --git a/setup.cfg b/setup.cfg
index fff1fcd..dd275b8 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -9,7 +9,7 @@ show_missing = true
 name = jandd.sphinxext.ip
 description = IP address extension for Sphinx
 long_description = file: README.rst, CHANGES.rst
-long_description_content_type = text/rst
+long_description_content_type = text/x-rst
 url = https://pypi.org/project/jandd.sphinxext.ip/
 author = Jan Dittberner
 author_email = jan@dittberner.info