diff --git a/asciidoctor-diagram-example/pom.xml b/asciidoctor-diagram-example/pom.xml
index 146df8b7..31f67f4a 100644
--- a/asciidoctor-diagram-example/pom.xml
+++ b/asciidoctor-diagram-example/pom.xml
@@ -12,7 +12,7 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <asciidoctor.maven.plugin.version>1.5.2.1</asciidoctor.maven.plugin.version>
         <asciidoctorj.version>1.5.3.2</asciidoctorj.version>
-        <jruby.version>9.0.4.0</jruby.version>
+        <jruby.version>1.7.21</jruby.version><!-- downgrade of JRuby see: https://github.com/asciidoctor/asciidoctorj/issues/409 -->
         <rubygems.asciidoctor.diagram.version>1.3.1</rubygems.asciidoctor.diagram.version>
     </properties>
 
diff --git a/asciidoctor-diagram-example/src/docs/asciidoc/example-manual.adoc b/asciidoctor-diagram-example/src/docs/asciidoc/example-manual.adoc
index a5f4b1db..7624a980 100644
--- a/asciidoctor-diagram-example/src/docs/asciidoc/example-manual.adoc
+++ b/asciidoctor-diagram-example/src/docs/asciidoc/example-manual.adoc
@@ -42,6 +42,16 @@ Alice -> Bob: Another authentication Request
 Alice <-- Bob: another authentication Response
 ....
 
+[graphviz, dot-example, svg]
+----
+digraph g {
+    a -> b
+    b -> c
+    c -> d
+    d -> a
+}
+----
+
 == Attributes
 
 .Built-in