diff --git a/Gemfile.lock b/Gemfile.lock
index 91ed5d63..35e83e75 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -55,7 +55,7 @@ GEM
     codecov (0.6.0)
       simplecov (>= 0.15, < 0.22)
     coderay (1.1.3)
-    concurrent-ruby (1.3.6)
+    concurrent-ruby (1.3.8)
     connection_pool (3.0.2)
     diff-lcs (1.6.2)
     docile (1.4.1)