diff --git a/asciidoctorj-pdf/gradle.properties b/asciidoctorj-pdf/gradle.properties
index 91bde32..a97c670 100644
--- a/asciidoctorj-pdf/gradle.properties
+++ b/asciidoctorj-pdf/gradle.properties
@@ -1,4 +1,4 @@
 properName=AsciidoctorJ PDF
 description=AsciidoctorJ PDF bundles the Asciidoctor PDF RubyGem (asciidoctor-pdf) so it can be loaded into the JVM using JRuby.
-version=2.1.4
+version=2.1.6
 gem_name=asciidoctor-pdf
diff --git a/build.gradle b/build.gradle
index 39b1c67..0f3e8b5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -40,14 +40,14 @@ ext {
 
   // gem versions
   asciidoctorJVersion = project.hasProperty('asciidoctorJVersion') ? project.asciidoctorJVersion : '2.5.3'
-  asciidoctorPdfGemVersion = project.hasProperty('asciidoctorPdfGemVersion') ? project.asciidoctorPdfGemVersion : '2.1.4'
+  asciidoctorPdfGemVersion = project.hasProperty('asciidoctorPdfGemVersion') ? project.asciidoctorPdfGemVersion : '2.1.6'
 
   addressableVersion = '2.8.0'
   concurrentRubyVersion = '1.1.7'
   public_suffixVersion = '1.4.6'
   prawnGemVersion=project.hasProperty('prawnGemVersion') ? project.prawnGemVersion : '2.4.0'
   rghostGemVersion = '0.9.7'
-  rougeGemVersion = '3.28.0'
+  rougeGemVersion = '3.29.0'
   spockVersion = '0.7-groovy-2.0'
   threadSafeGemVersion = '0.3.6'
   ttfunkGemVersion = '1.7.0'
diff --git a/gradle.properties b/gradle.properties
index 651dd05..770b407 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,3 +1,3 @@
-version=2.1.4
+version=2.1.6
 sourceCompatibility=1.8
 targetCompatibility=1.8