diff --git a/Gemfile.lock b/Gemfile.lock
index 8987036..665abc8 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    asciidoctor (1.5.6.1)
+    asciidoctor (1.5.8)
     asciidoctor-diagram (1.5.7)
       asciidoctor (~> 1.5.0)
     coderay (1.1.2)