diff --git a/Gemfile.lock b/Gemfile.lock
index e25bc328a..59820e8ea 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -113,7 +113,7 @@ GEM
       rack-test (>= 0.6.3)
       regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
-    concurrent-ruby (1.3.5)
+    concurrent-ruby (1.3.6)
     connection_pool (3.0.2)
     crass (1.0.6)
     cuprite (0.17)