diff --git a/Gemfile.lock b/Gemfile.lock
index e02f425..3a45e44 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -25,7 +25,7 @@ GEM
     base64 (0.3.0)
     benchmark (0.4.1)
     bigdecimal (3.2.1)
-    concurrent-ruby (1.3.5)
+    concurrent-ruby (1.3.7)
     connection_pool (2.5.3)
     diff-lcs (1.6.2)
     drb (2.2.3)