diff --git a/CHANGELOG.md b/CHANGELOG.md
index 77ccd3d..96ac9ff 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Add `external` class to the "Website Source" link in footer.
 - Add ability to enable inline table of contents in articles (#94 and #95).
 - Add ability to make table of contents use numbered lists (#95).
 - Add ability to open search by pressing the slash key.
diff --git a/templates/partials/footer.html b/templates/partials/footer.html
index 902aa7b..8a309b0 100644
--- a/templates/partials/footer.html
+++ b/templates/partials/footer.html
@@ -39,7 +39,7 @@
 
 	{%- if config.extra.source_url and config.extra.footer.show_source %}
 		<p>
-			<a href="{{ config.extra.source_url }}" rel="{{ rel_attributes }}">
+			<a class="external" href="{{ config.extra.source_url }}" rel="{{ rel_attributes }}">
 				{{- macros_translate::translate(key="source", default="Website source", language_strings=language_strings) -}}
 			</a>
 		</p>