diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index 22e7305b988ea5c6c833c7e495a7c274768c0a87..ad8d474b846e5b4bf2247e1c27fd60b2077325ff 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -29,7 +29,7 @@ module OS
 
     def prerelease?
       # TODO: bump version when new OS is released
-      version >= "10.12"
+      version >= "10.13"
     end
 
     def outdated_release?