diff --git a/spec/pom.xml b/spec/pom.xml
index aaee443..c62f378 100644
--- a/spec/pom.xml
+++ b/spec/pom.xml
@@ -44,12 +44,11 @@
             <plugin>
                 <groupId>org.asciidoctor</groupId>
                 <artifactId>asciidoctor-maven-plugin</artifactId>
-                <version>2.1.0</version>
                 <dependencies>
                     <dependency>
                         <groupId>org.asciidoctor</groupId>
                         <artifactId>asciidoctorj-pdf</artifactId>
-                        <version>1.5.3</version>
+                        <version>2.3.9</version>
                     </dependency>
                 </dependencies>
                 <executions>