diff --git a/Gemfile.lock b/Gemfile.lock
index 2cbb71a..3cb7dc3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -69,7 +69,7 @@ GEM
     rack (2.0.8)
     rainbow (3.0.0)
     rake (13.0.1)
-    rdoc (6.1.1)
+    rdoc (6.3.1)
     rspec (3.8.0)
       rspec-core (~> 3.8.0)
       rspec-expectations (~> 3.8.0)