diff --git a/Library/Homebrew/Gemfile.lock b/Library/Homebrew/Gemfile.lock
index 2d2ba02155..8b148ee9d1 100644
--- a/Library/Homebrew/Gemfile.lock
+++ b/Library/Homebrew/Gemfile.lock
@@ -18,7 +18,7 @@ GEM
     colorize (0.8.1)
     commander (4.6.0)
       highline (~> 2.0.0)
-    concurrent-ruby (1.1.8)
+    concurrent-ruby (1.1.9)
     connection_pool (2.2.5)
     diff-lcs (1.4.4)
     docile (1.3.5)