diff --git a/rackup.gemspec b/rackup.gemspec
index 1a27c35..6d23cfe 100644
--- a/rackup.gemspec
+++ b/rackup.gemspec
@@ -18,6 +18,10 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = ">= 2.5"
 
+  spec.metadata = {
+    "rubygems_mfa_required" => "true"
+  }
+
   spec.add_dependency "rack", ">= 3"
   spec.add_dependency "webrick", "~> 1.8"