diff --git a/doc/api/Gemfile.lock b/doc/api/Gemfile.lock
index 9c952da..6771262 100644
--- a/doc/api/Gemfile.lock
+++ b/doc/api/Gemfile.lock
@@ -31,7 +31,7 @@ GEM
     hashie (3.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    kramdown (2.3.0)
+    kramdown (2.3.1)
       rexml
     listen (3.0.8)
       rb-fsevent (~> 0.9, >= 0.9.4)