diff --git a/Gemfile.lock b/Gemfile.lock
index e83c8cb9..9d66cc45 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -528,7 +528,7 @@ GEM
       ffi (~> 1.0)
     rb-readline (0.5.5)
     rbtree3 (0.7.1)
-    rdoc (6.6.2)
+    rdoc (6.6.3.1)
       psych (>= 4.0.0)
     regexp_parser (2.9.0)
     reline (0.4.2)