diff --git a/Library/mma_lib.rb b/Library/mma_lib.rb
index c5be123..8cd21af 100644
--- a/Library/mma_lib.rb
+++ b/Library/mma_lib.rb
@@ -1,4 +1,4 @@
-# typed: true
+# typed: strict
 # frozen_string_literal: true
 
 require "formula"