diff --git a/Gemfile.lock b/Gemfile.lock
index cfdf13dc58e..456682edf66 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -963,7 +963,7 @@ GEM
       msgpack (>= 0.4.3)
       optimist (>= 3.0.0)
     rbtree3 (0.7.1)
-    rdoc (6.9.0)
+    rdoc (6.9.1)
       psych (>= 4.0.0)
     recaptcha (5.18.0)
     redcarpet (3.6.0)