diff --git a/docker/conf/apache2/sites-available/noblogs.org.conf b/docker/conf/apache2/sites-available/noblogs.org.conf
index d413a8c574415a33eb3bfe97fb4bda72c72d6d03..e533ff1fc286d6dae75320ce485af2c8d4e7a3b2 100644
--- a/docker/conf/apache2/sites-available/noblogs.org.conf
+++ b/docker/conf/apache2/sites-available/noblogs.org.conf
@@ -23,5 +23,10 @@
                 Options -Indexes
         </Directory>
 
+	# Support ActivityPub content negotiation on user profiles.
+	<Location /post/author/>
+		Header append Vary "Accept"
+	</Location>
+
 </VirtualHost>