diff --git a/doc/changes/unreleased.md b/doc/changes/unreleased.md
index 9aff33456..4e5b64a91 100644
--- a/doc/changes/unreleased.md
+++ b/doc/changes/unreleased.md
@@ -41,4 +41,5 @@
 
 ## 🐞 Fixed
 
+* Fixed `index.rst` documentation template to provide the correct underlining length of the main heading
 * Added multi-version extension to Sphinx configuration of the project template
diff --git a/project-template/{{cookiecutter.repo_name}}/doc/index.rst b/project-template/{{cookiecutter.repo_name}}/doc/index.rst
index f41dbcef0..e224a7558 100644
--- a/project-template/{{cookiecutter.repo_name}}/doc/index.rst
+++ b/project-template/{{cookiecutter.repo_name}}/doc/index.rst
@@ -1,5 +1,5 @@
 Documentation of  {{cookiecutter.project_name}}
-------------------{{ '-' * cookiecutter.package_name | length }}
+------------------{{ '-' * cookiecutter.project_name | length }}
 
 .. grid:: 1 1 3 2
     :gutter: 2
@@ -33,4 +33,3 @@ Documentation of  {{cookiecutter.project_name}}
    api
    faq
    changes/changelog
-