diff --git a/Library/Homebrew/requirements/xcode_requirement.rb b/Library/Homebrew/requirements/xcode_requirement.rb
index 0d74f0e945..b5514b925a 100644
--- a/Library/Homebrew/requirements/xcode_requirement.rb
+++ b/Library/Homebrew/requirements/xcode_requirement.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 require "requirement"
@@ -7,6 +7,7 @@ require "requirement"
 class XcodeRequirement < Requirement
   fatal true
 
+  sig { returns(T.nilable(String)) }
   attr_reader :version
 
   satisfy(build_env: false) do
@@ -14,8 +15,10 @@ class XcodeRequirement < Requirement
     xcode_installed_version
   end
 
+  sig { params(tags: T::Array[String]).void }
   def initialize(tags = [])
-    @version = tags.shift if tags.first.to_s.match?(/(\d\.)+\d/)
+    version = tags.shift if tags.first.to_s.match?(/(\d\.)+\d/)
+    @version = T.let(version, T.nilable(String))
     super
   end
 
@@ -53,6 +56,7 @@ class XcodeRequirement < Requirement
     "#<#{self.class.name}: version>=#{@version.inspect} #{tags.inspect}>"
   end
 
+  sig { returns(String) }
   def display_s
     return "#{name.capitalize} (on macOS)" unless @version