diff --git a/Library/Homebrew/cask/dsl/conflicts_with.rb b/Library/Homebrew/cask/dsl/conflicts_with.rb
index d5de4edeb9..f49f3a0620 100644
--- a/Library/Homebrew/cask/dsl/conflicts_with.rb
+++ b/Library/Homebrew/cask/dsl/conflicts_with.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "delegate"
+
 require "extend/hash_validator"
 using HashValidator
 
@@ -8,7 +10,7 @@ module Cask
     # Class corresponding to the `conflicts_with` stanza.
     #
     # @api private
-    class ConflictsWith < DelegateClass(Hash)
+    class ConflictsWith < SimpleDelegator
       VALID_KEYS = [
         :formula,
         :cask,
@@ -18,12 +20,13 @@ module Cask
         :java,
       ].freeze
 
-      def initialize(**pairs)
-        pairs.assert_valid_keys!(*VALID_KEYS)
+      def initialize(**options)
+        options.assert_valid_keys!(*VALID_KEYS)
 
-        super(pairs.transform_values { |v| Set.new(Array(v)) })
+        conflicts = options.transform_values { |v| Set.new(Array(v)) }
+        conflicts.default = Set.new
 
-        self.default = Set.new
+        super(conflicts)
       end
 
       def to_json(generator)
diff --git a/Library/Homebrew/cask/dsl/depends_on.rb b/Library/Homebrew/cask/dsl/depends_on.rb
index e8beba968d..a3721b0530 100644
--- a/Library/Homebrew/cask/dsl/depends_on.rb
+++ b/Library/Homebrew/cask/dsl/depends_on.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "delegate"
+
 require "requirements/macos_requirement"
 
 module Cask
@@ -7,7 +9,7 @@ module Cask
     # Class corresponding to the `depends_on` stanza.
     #
     # @api private
-    class DependsOn < DelegateClass(Hash)
+    class DependsOn < SimpleDelegator
       VALID_KEYS = Set.new([
                              :formula,
                              :cask,
diff --git a/Library/Homebrew/dependencies.rb b/Library/Homebrew/dependencies.rb
index 6a39871b13..07d79190d5 100644
--- a/Library/Homebrew/dependencies.rb
+++ b/Library/Homebrew/dependencies.rb
@@ -6,7 +6,7 @@ require "cask_dependent"
 # A collection of dependencies.
 #
 # @api private
-class Dependencies < DelegateClass(Array)
+class Dependencies < SimpleDelegator
   def initialize(*args)
     super(args)
   end
@@ -41,7 +41,7 @@ end
 # A collection of requirements.
 #
 # @api private
-class Requirements < DelegateClass(Set)
+class Requirements < SimpleDelegator
   def initialize(*args)
     super(Set.new(args))
   end
diff --git a/Library/Homebrew/sorbet/rbi/utils/user.rbi b/Library/Homebrew/sorbet/rbi/utils/user.rbi
index 49e9f1b3f4..ef1997fafd 100644
--- a/Library/Homebrew/sorbet/rbi/utils/user.rbi
+++ b/Library/Homebrew/sorbet/rbi/utils/user.rbi
@@ -1,9 +1,11 @@
 # typed: strict
 
-class User < String
-  def gui?
-  end
+class User < SimpleDelegator
+  include Kernel
 
-  def self.current
-  end
+  sig { returns(T::Boolean) }
+  def gui?; end
+
+  sig { returns(T.nilable(T.attached_class)) }
+  def self.current; end
 end
diff --git a/Library/Homebrew/utils/user.rb b/Library/Homebrew/utils/user.rb
index 0d5b94fb34..d40a7b6072 100644
--- a/Library/Homebrew/utils/user.rb
+++ b/Library/Homebrew/utils/user.rb
@@ -8,7 +8,7 @@ require "system_command"
 # A system user.
 #
 # @api private
-class User < DelegateClass(String)
+class User < SimpleDelegator
   # Return whether the user has an active GUI session.
   def gui?
     out, _, status = system_command "who"