diff --git a/docs/build.gradle b/docs/build.gradle
index ffd9fd4..056cb92 100644
--- a/docs/build.gradle
+++ b/docs/build.gradle
@@ -5,7 +5,7 @@ buildscript {
     dependencies {
         classpath 'org.asciidoctor:asciidoctor-gradle-plugin:1.5.3'
         classpath 'org.asciidoctor:asciidoctorj-epub3:1.5.1'
-        classpath 'org.asciidoctor:asciidoctorj-pdf:1.5.0-alpha.11'
+        classpath 'org.asciidoctor:asciidoctorj-pdf:2.3.9'
     }
 }