diff --git a/Gemfile.lock b/Gemfile.lock
index d21b25e..2519b18 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -38,6 +38,7 @@ GEM
     arel (4.0.2)
     builder (3.1.4)
     coderay (1.1.0)
+    concurrent-ruby (1.1.5)
     database_cleaner (1.3.0)
     diff-lcs (1.2.5)
     docile (1.1.5)
@@ -89,7 +90,8 @@ GEM
       simplecov-html (~> 0.8.0)
     simplecov-html (0.8.0)
     slop (3.6.0)
-    sprockets (3.4.0)
+    sprockets (3.7.2)
+      concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (2.3.3)
       actionpack (>= 3.0)