diff --git a/Gemfile.lock b/Gemfile.lock
index ede0c8b..3eb58b1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -73,14 +73,14 @@ GEM
       multi_json (~> 1.3)
       multi_xml (~> 0.5)
       rack (>= 1.2, < 4)
-    psych (5.1.1.1)
+    psych (5.1.2)
       stringio
     public_suffix (5.0.3)
     racc (1.7.3)
     rack (3.0.8)
     rake (13.1.0)
     rchardet (1.8.0)
-    rdoc (6.6.0)
+    rdoc (6.6.3.1)
       psych (>= 4.0.0)
     rexml (3.2.6)
     rspec (3.12.0)
@@ -104,7 +104,7 @@ GEM
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
-    stringio (3.0.9)
+    stringio (3.1.0)
     thread_safe (0.3.6)
     vcr (6.2.0)
     webmock (3.19.1)