diff --git a/Gemfile.lock b/Gemfile.lock
index 69dfd15..ad5a6e6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -9,7 +9,7 @@ GEM
   specs:
     addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
-    concurrent-ruby (1.1.10)
+    concurrent-ruby (1.3.7)
     diff-lcs (1.4.4)
     domain_name (0.5.20190701)
       unf (>= 0.0.5, < 1.0.0)