diff --git a/samples/testng/build.gradle b/samples/testng/build.gradle
index b85ec5d4..8381266a 100644
--- a/samples/testng/build.gradle
+++ b/samples/testng/build.gradle
@@ -8,7 +8,7 @@ buildscript {
 }
 
 plugins {
-	id "org.asciidoctor.convert" version "1.5.3"
+	id "org.asciidoctor.convert" version "1.5.9.2"
 }
 
 apply plugin: 'java'
diff --git a/samples/web-test-client/build.gradle b/samples/web-test-client/build.gradle
index 90f07d3c..8a89a074 100644
--- a/samples/web-test-client/build.gradle
+++ b/samples/web-test-client/build.gradle
@@ -1,5 +1,5 @@
 plugins {
-	id "org.asciidoctor.convert" version "1.5.3"
+	id "org.asciidoctor.convert" version "1.5.9.2"
 }
 
 apply plugin: 'java'