diff --git a/wrk2.rb b/wrk2.rb
index f879041..adf8be4 100644
--- a/wrk2.rb
+++ b/wrk2.rb
@@ -7,6 +7,9 @@ class Wrk2 < Formula
   depends_on "openssl"
 
   def install
+    # Per https://luajit.org/install.html: If MACOSX_DEPLOYMENT_TARGET
+    # is not set then it's forced to 10.4, which breaks compile on Mojave.
+    ENV["MACOSX_DEPLOYMENT_TARGET"] = MacOS.version
     system "make"
     mv "wrk", "wrk2"
     bin.install "wrk2"