diff --git a/Gemfile.lock b/Gemfile.lock
index 4c21de4..4902734 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -10,7 +10,7 @@ GEM
     ast (2.4.2)
     childprocess (5.1.0)
       logger (~> 1.5)
-    concurrent-ruby (1.3.3)
+    concurrent-ruby (1.3.4)
     csv (3.3.0)
     diff-lcs (1.5.1)
     docile (1.4.1)