diff --git a/Gemfile.lock b/Gemfile.lock
index 213c47b751..dd9813bf21 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -577,7 +577,7 @@ GEM
     rdf (3.3.1)
       bcp47_spec (~> 0.2)
       link_header (~> 0.0, >= 0.0.8)
-    rdoc (6.6.2)
+    rdoc (6.6.3.1)
       psych (>= 4.0.0)
     redcarpet (3.6.0)
     redis (5.1.0)