diff --git a/docs/Gemfile.lock b/docs/Gemfile.lock
index d608de1..a2e8c1f 100644
--- a/docs/Gemfile.lock
+++ b/docs/Gemfile.lock
@@ -8,7 +8,7 @@ GEM
       tzinfo (~> 1.1)
     addressable (2.5.2)
       public_suffix (>= 2.0.2, < 4.0)
-    asciidoctor (1.5.7.1)
+    asciidoctor (1.5.8)
     asciidoctor-diagram (1.5.12)
       asciidoctor (~> 1.5.0)
     coderay (1.1.2)