diff --git a/.circleci/config.yml b/.circleci/config.yml
index 363ff79..74869c4 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -8,7 +8,7 @@ commands:
         type: string
       sphinx-version:
         type: string
-        default: "5,6,7,latest"
+        default: "5,6,7,8,latest,dev"
     steps:
       - checkout
       # NOTE: use Tox 3.x until I understand the syntax for generative environments:
@@ -23,12 +23,14 @@ jobs:
     steps:
       - run-tox:
           version: py38
+          sphinx-version: "5,6"
   py39:
     docker:
       - image: 'cimg/python:3.9'
     steps:
       - run-tox:
           version: py39
+          sphinx-version: "5,6,7"
   py310:
     docker:
       - image: 'cimg/python:3.10'
diff --git a/.gitignore b/.gitignore
index 6cb47a2..c904c41 100644
--- a/.gitignore
+++ b/.gitignore
@@ -108,4 +108,7 @@ package-lock.json
 node_modules
 
 # vscode
-.vscode/
\ No newline at end of file
+.vscode/
+
+# PyPI build
+_build/
\ No newline at end of file
diff --git a/tests/examples/404rst/conf.py b/tests/examples/404rst/conf.py
index ba27a90..99956a6 100644
--- a/tests/examples/404rst/conf.py
+++ b/tests/examples/404rst/conf.py
@@ -1,5 +1,6 @@
 # conf.py to run tests
 
+project = 'Python'
 master_doc = 'index'
 extensions = [
     'notfound.extension',
diff --git a/tests/examples/default/conf.py b/tests/examples/default/conf.py
index eaf730d..7d7a172 100644
--- a/tests/examples/default/conf.py
+++ b/tests/examples/default/conf.py
@@ -1,5 +1,6 @@
 # conf.py to run tests
 
+project = 'Python'
 master_doc = 'index'
 extensions = [
     'notfound.extension',
diff --git a/tests/test_urls.py b/tests/test_urls.py
index 80a2e73..d5a4031 100644
--- a/tests/test_urls.py
+++ b/tests/test_urls.py
@@ -64,6 +64,11 @@ def test_default_settings(app, status, warning):
     else:
         cssclass = ""
 
+    if sphinx.version_info < (7, 3):
+        alt = "Logo"
+    else:
+        alt = "Logo of Python"
+
     chunks = [
         '<h1>Page not found</h1>',
         "Unfortunately we couldn't find the content you were looking for.",
@@ -71,7 +76,7 @@ def test_default_settings(app, status, warning):
 
         # favicon and logo
         f'<link rel="{cssclass}icon" href="/en/latest/_static/favicon.png"/>',
-        '<img class="logo" src="/en/latest/_static/logo.svg" alt="Logo"/>',
+        f'<img class="logo" src="/en/latest/_static/logo.svg" alt="{alt}"/>',
 
         # sidebar URLs
         '<h1 class="logo"><a href="/en/latest/index.html">Python</a></h1>',
@@ -139,6 +144,11 @@ def test_urls_prefix_setting(app, status, warning):
     else:
         cssclass = ""
 
+    if sphinx.version_info < (7, 3):
+        alt = "Logo"
+    else:
+        alt = "Logo of Python"
+
     chunks = [
         # sidebar URLs
         '<h1 class="logo"><a href="/language/version/index.html">Python</a></h1>',
@@ -147,7 +157,7 @@ def test_urls_prefix_setting(app, status, warning):
 
         # favicon and logo
         f'<link rel="{cssclass}icon" href="/language/version/_static/favicon.png"/>',
-        '<img class="logo" src="/language/version/_static/logo.svg" alt="Logo"/>',
+        f'<img class="logo" src="/language/version/_static/logo.svg" alt="{alt}"/>',
 
         # resources
         _get_css_html_link_tag(app, 'language', 'version', 'alabaster.css'),
@@ -177,6 +187,12 @@ def test_urls_prefix_setting_none(app, status, warning):
     else:
         cssclass = ""
 
+    if sphinx.version_info < (7, 3):
+        alt = "Logo"
+    else:
+        alt = "Logo of Python"
+
+
     chunks = [
         # sidebar URLs
         '<h1 class="logo"><a href="/index.html">Python</a></h1>',
@@ -185,7 +201,7 @@ def test_urls_prefix_setting_none(app, status, warning):
 
         # favicon and logo
         f'<link rel="{cssclass}icon" href="/_static/favicon.png"/>',
-        '<img class="logo" src="/_static/logo.svg" alt="Logo"/>',
+        f'<img class="logo" src="/_static/logo.svg" alt="{alt}"/>',
 
         # resources
         _get_css_html_link_tag(app, '', '', 'alabaster.css'),
diff --git a/tox.ini b/tox.ini
index a25b197..a2107a8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,9 @@ isolated_build = True
 
 envlist =
   docs
-  py{38,39,310,311,312}-sphinx{5,6,7,latest}
+  py{38}-sphinx{5,6}
+  py{39}-sphinx{5,6,7}
+  py{310,311,312}-sphinx{5,6,7,8,latest,dev}
 
 [testenv]
 deps =
@@ -15,7 +17,9 @@ deps =
   sphinx5: sphinx<6.0
   sphinx6: sphinx<7.0
   sphinx7: sphinx<8.0
+  sphinx8: sphinx<9.0
   sphinxlatest: sphinx
+  sphinxdev: https://github.com/sphinx-doc/sphinx/archive/refs/heads/master.zip
 commands = pytest {posargs}
 
 [testenv:docs]