diff --git a/Gemfile.lock b/Gemfile.lock
index ff30c7b54..a1ed56ea6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -139,7 +139,7 @@ GEM
       rack (>= 1.3)
     rainbow (3.1.1)
     rake (13.1.0)
-    rdoc (6.6.2)
+    rdoc (6.6.3.1)
       psych (>= 4.0.0)
     regexp_parser (2.9.0)
     reline (0.4.3)