diff --git a/Library/Homebrew/extend/os/linux/formula_installer.rb b/Library/Homebrew/extend/os/linux/formula_installer.rb
index 718e4bf30242f..6cae06010d8c4 100644
--- a/Library/Homebrew/extend/os/linux/formula_installer.rb
+++ b/Library/Homebrew/extend/os/linux/formula_installer.rb
@@ -1,9 +1,7 @@
-# typed: true # rubocop:disable Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 class FormulaInstaller
-  undef fresh_install?
-
   sig { params(formula: Formula).returns(T.nilable(T::Boolean)) }
   def fresh_install?(formula)
     !Homebrew::EnvConfig.developer? &&