diff --git a/Library/Homebrew/Gemfile.lock b/Library/Homebrew/Gemfile.lock
index d6a2cc26ee..27130421f0 100644
--- a/Library/Homebrew/Gemfile.lock
+++ b/Library/Homebrew/Gemfile.lock
@@ -8,7 +8,7 @@ GEM
       tzinfo (~> 1.1)
     ast (2.4.0)
     backports (3.12.0)
-    concurrent-ruby (1.1.4)
+    concurrent-ruby (1.1.5)
     connection_pool (2.2.2)
     coveralls (0.8.22)
       json (>= 1.8, < 3)