diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index 22e7305b98..ad8d474b84 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?