diff --git a/Gemfile.lock b/Gemfile.lock
index dbd41f894d3..392343a08e4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,7 +4,7 @@ GEM
     addressable (2.8.4)
       public_suffix (>= 2.0.2, < 6.0)
     ansi (1.5.0)
-    asciidoctor (2.0.20)
+    asciidoctor (2.0.21)
     asciidoctor-jenkins-extensions (0.9.0)
       asciidoctor (>= 1.5.5)
       coderay (~> 1.1.1)