diff --git a/Gemfile.lock b/Gemfile.lock
index 624f6fd..63ca9f8 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -84,7 +84,7 @@ GEM
     power_assert (1.1.1)
     rack (1.6.8)
     rake (10.3.2)
-    rdoc (4.3.0)
+    rdoc (6.3.2)
     redcarpet (3.4.0)
     rspec (3.1.0)
       rspec-core (~> 3.1.0)