diff --git a/CHANGES b/CHANGES
index f2e1585..30caf3e 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,8 @@
+Release 2.0.6 (unreleased)
+==========================
+
+* Fix tests for Sphinx 7.4 and later.
+
 Release 2.0.5 (2024-01-13)
 ==========================
 
diff --git a/sphinxcontrib/htmlhelp/__init__.py b/sphinxcontrib/htmlhelp/__init__.py
index dd27da2..36e80b3 100644
--- a/sphinxcontrib/htmlhelp/__init__.py
+++ b/sphinxcontrib/htmlhelp/__init__.py
@@ -286,7 +286,7 @@ def write_param(name: str, value: str) -> None:
                     f.write('</UL>')
             for (key, group) in index:
                 for title, (refs, subitems, key_) in group:
-                    write_index(title, refs, subitems)
+                    write_index(title, refs, subitems)  # type: ignore[arg-type]
             f.write('</UL>\n')
 
 
diff --git a/tests/roots/test-basic/conf.py b/tests/roots/test-basic/conf.py
index e69de29..329280d 100644
--- a/tests/roots/test-basic/conf.py
+++ b/tests/roots/test-basic/conf.py
@@ -0,0 +1 @@
+project = 'Python'
diff --git a/tests/roots/test-hhc/conf.py b/tests/roots/test-hhc/conf.py
index 20447e0..7825564 100644
--- a/tests/roots/test-hhc/conf.py
+++ b/tests/roots/test-hhc/conf.py
@@ -1 +1,2 @@
+project = 'Python'
 html_short_title = "Sphinx's documentation"