diff --git a/Gemfile.lock b/Gemfile.lock
index b57acd4..0280994 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -54,7 +54,7 @@ GEM
     racc (1.7.3)
     rainbow (3.1.1)
     rake (13.1.0)
-    rdoc (6.6.2)
+    rdoc (6.6.3.1)
       psych (>= 4.0.0)
     regexp_parser (2.8.3)
     reline (0.4.1)