diff --git a/antora-playbook.yml b/antora-playbook.yml
index a355b173f..1f4bdf8e2 100644
--- a/antora-playbook.yml
+++ b/antora-playbook.yml
@@ -25,6 +25,7 @@ asciidoc:
   extensions:
   - '@asciidoctor/tabs'
   - '@springio/asciidoctor-extensions'
+  - '@springio/asciidoctor-extensions/javadoc-extension'
 urls:
   latest_version_segment_strategy: redirect:to
   latest_version_segment: ''