diff --git a/Gemfile.lock b/Gemfile.lock
index 12e9bf6a..c3b1d586 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -38,7 +38,7 @@ GEM
     builder (3.2.4)
     byebug (11.1.3)
     coderay (1.1.3)
-    concurrent-ruby (1.2.2)
+    concurrent-ruby (1.3.7)
     connection_pool (2.4.1)
     drb (2.1.1)
       ruby2_keywords