diff --git a/common/sphinx_rtd_theme_rtems/layout.html b/common/sphinx_rtd_theme_rtems/layout.html
index 0fe6c65..3542bea 100644
--- a/common/sphinx_rtd_theme_rtems/layout.html
+++ b/common/sphinx_rtd_theme_rtems/layout.html
@@ -67,7 +67,11 @@
   {%- endblock %}
 
   {# CSS #}
-  <link rel="stylesheet" href="{{ pathto('_static/' + style, 1) }}" type="text/css" />
+  {%- if sphinx_version <= "5.9.0" -%}
+   <link rel="stylesheet" href="{{ pathto('_static/' + style, 1) }}" type="text/css" />
+  {%- else %}
+   <link rel="stylesheet" href="{{ pathto('_static/' + styles[-1], 1) }}" type="text/css" />
+  {%- endif %}
   <link rel="stylesheet" href="{{ pathto('_static/pygments.css', 1) }}" type="text/css" />
   {%- for css in css_files %}
     {%- if css|attr("rel") %}
diff --git a/common/waf.py b/common/waf.py
index 6efe038..5f811f6 100644
--- a/common/waf.py
+++ b/common/waf.py
@@ -16,11 +16,9 @@ from waflib.Build import BuildContext
 import latex
 import conf
 
-# Sphinx >= 6 are currently broken. 
 # If you do not want to check for a maximum version, set it to None.
 sphinx_min_version = (1, 3)
-sphinx_max_version = (5, 9)
-#sphinx_max_version = None
+sphinx_max_version = None
 
 def version_cmdline(ctx):
     return '-Drelease="%s" -Dversion="%s" -Drtems_major="%s" ' \