diff --git a/Gemfile.lock b/Gemfile.lock
index c521dff..9c60952 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -21,7 +21,7 @@ GEM
     coffee-script-source (1.11.1)
     colorator (1.1.0)
     commonmarker (0.23.10)
-    concurrent-ruby (1.2.3)
+    concurrent-ruby (1.3.7)
     connection_pool (2.4.1)
     dnsruby (1.70.0)
       simpleidn (~> 0.2.1)