diff --git a/Gemfile.lock b/Gemfile.lock
index 79f03f25..a79eba3e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -95,7 +95,7 @@ GEM
       rack-test (>= 0.6.3)
       regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
-    concurrent-ruby (1.3.4)
+    concurrent-ruby (1.3.5)
     connection_pool (2.5.0)
     crass (1.0.6)
     date (3.4.1)