diff --git a/Library/Homebrew/rubocops/cask/ast/cask_block.rb b/Library/Homebrew/rubocops/cask/ast/cask_block.rb
index 943c09185a..8925ad4686 100644
--- a/Library/Homebrew/rubocops/cask/ast/cask_block.rb
+++ b/Library/Homebrew/rubocops/cask/ast/cask_block.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 require "forwardable"
@@ -33,10 +33,13 @@ module RuboCop
             ->(node) { node.parent == block_node }
           end
 
-          @stanzas ||= block_body.each_node
-                                 .select(&:stanza?)
-                                 .select(&is_stanza)
-                                 .map { |node| Stanza.new(node, comments) }
+          @stanzas ||= T.let(
+            block_body.each_node
+                      .select(&:stanza?)
+                      .select(&is_stanza)
+                      .map { |node| Stanza.new(node, comments) },
+            T.nilable(T::Array[Stanza]),
+          )
         end
       end
 
@@ -46,17 +49,20 @@ module RuboCop
       class CaskBlock < StanzaBlock
         extend Forwardable
 
+        sig { returns(RuboCop::AST::BlockNode) }
         def cask_node
           block_node
         end
 
         def_delegator :cask_node, :block_body, :cask_body
 
+        sig { returns(CaskHeader) }
         def header
-          @header ||= CaskHeader.new(block_node.method_node)
+          @header ||= T.let(CaskHeader.new(block_node.method_node), T.nilable(CaskHeader))
         end
 
         # TODO: Use `StanzaBlock#stanzas` for all cops, where possible.
+        sig { returns(T::Array[Stanza]) }
         def stanzas
           return [] unless cask_body
 
@@ -65,6 +71,7 @@ module RuboCop
                                 .map { |node| Stanza.new(node, comments) }
         end
 
+        sig { returns(T::Array[Stanza]) }
         def toplevel_stanzas
           # If a `cask` block only contains one stanza, it is that stanza's direct parent,
           # otherwise stanzas are grouped in a block and `cask` is that block's parent.
@@ -74,7 +81,7 @@ module RuboCop
             ->(stanza) { stanza.parent_node.cask_block? }
           end
 
-          @toplevel_stanzas ||= stanzas.select(&is_toplevel_stanza)
+          @toplevel_stanzas ||= T.let(stanzas.select(&is_toplevel_stanza), T.nilable(T::Array[Stanza]))
         end
       end
     end
diff --git a/Library/Homebrew/rubocops/cask/desc.rb b/Library/Homebrew/rubocops/cask/desc.rb
index 64149fc0eb..b032485d5c 100644
--- a/Library/Homebrew/rubocops/cask/desc.rb
+++ b/Library/Homebrew/rubocops/cask/desc.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 require "rubocops/cask/mixin/on_desc_stanza"
@@ -14,8 +14,9 @@ module RuboCop
         include DescHelper
         extend AutoCorrector
 
+        sig { params(stanza: RuboCop::Cask::AST::Stanza).void }
         def on_desc_stanza(stanza)
-          @name = cask_block.header.cask_token
+          @name = T.let(cask_block.header.cask_token, T.nilable(String))
           desc_call = stanza.stanza_node
           audit_desc(:cask, @name, desc_call)
         end
diff --git a/Library/Homebrew/rubocops/cask/homepage_url_styling.rb b/Library/Homebrew/rubocops/cask/homepage_url_styling.rb
index 98820f5c73..efb82b7b94 100644
--- a/Library/Homebrew/rubocops/cask/homepage_url_styling.rb
+++ b/Library/Homebrew/rubocops/cask/homepage_url_styling.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 require "forwardable"
@@ -17,8 +17,9 @@ module RuboCop
 
         MSG_NO_SLASH = "'%<url>s' must have a slash after the domain."
 
+        sig { params(stanza: RuboCop::Cask::AST::Stanza).void }
         def on_homepage_stanza(stanza)
-          @name = cask_block.header.cask_token
+          @name = T.let(cask_block.header.cask_token, T.nilable(String))
           desc_call = stanza.stanza_node
           url_node = desc_call.first_argument
 
diff --git a/Library/Homebrew/rubocops/cask/mixin/on_url_stanza.rb b/Library/Homebrew/rubocops/cask/mixin/on_url_stanza.rb
index ad2223644b..26e2b3b30d 100644
--- a/Library/Homebrew/rubocops/cask/mixin/on_url_stanza.rb
+++ b/Library/Homebrew/rubocops/cask/mixin/on_url_stanza.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 module RuboCop
@@ -9,8 +9,9 @@ module RuboCop
         extend Forwardable
         include CaskHelp
 
+        sig { override.params(cask_block: T.nilable(RuboCop::Cask::AST::CaskBlock)).void }
         def on_cask(cask_block)
-          @cask_block = cask_block
+          @cask_block = T.let(cask_block, T.nilable(RuboCop::Cask::AST::CaskBlock))
 
           toplevel_stanzas.select(&:url?).each do |stanza|
             on_url_stanza(stanza)
@@ -19,6 +20,7 @@ module RuboCop
 
         private
 
+        sig { returns(T.nilable(RuboCop::Cask::AST::CaskBlock)) }
         attr_reader :cask_block
 
         def_delegators :cask_block,
diff --git a/Library/Homebrew/rubocops/cask/no_overrides.rb b/Library/Homebrew/rubocops/cask/no_overrides.rb
index 382de67878..6f313f41ed 100644
--- a/Library/Homebrew/rubocops/cask/no_overrides.rb
+++ b/Library/Homebrew/rubocops/cask/no_overrides.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 module RuboCop
@@ -17,6 +17,7 @@ module RuboCop
                   "Add it to an `on_{system}` block instead. " \
                   "Use `:or_older` or `:or_newer` to specify a range of macOS versions."
 
+        sig { override.params(cask_block: RuboCop::Cask::AST::CaskBlock).void }
         def on_cask(cask_block)
           cask_stanzas = cask_block.toplevel_stanzas
 
@@ -34,8 +35,9 @@ module RuboCop
           end
         end
 
+        sig { params(on_system: T::Array[RuboCop::Cask::AST::Stanza]).returns(T::Set[Symbol]) }
         def on_system_stanzas(on_system)
-          names = Set.new
+          names = T.let(Set.new, T::Set[Symbol])
           method_nodes = on_system.map(&:method_node)
           method_nodes.select(&:block_type?).each do |node|
             node.child_nodes.each do |child|
@@ -56,14 +58,17 @@ module RuboCop
           names
         end
 
+        sig { params(node: RuboCop::AST::Node).returns(T::Boolean) }
         def inside_livecheck_defined?(node)
           single_stanza_livecheck_defined?(node) || multi_stanza_livecheck_defined?(node)
         end
 
+        sig { params(node: RuboCop::AST::Node).returns(T::Boolean) }
         def single_stanza_livecheck_defined?(node)
           node.parent.block_type? && node.parent.method_name == :livecheck
         end
 
+        sig { params(node: RuboCop::AST::Node).returns(T::Boolean) }
         def multi_stanza_livecheck_defined?(node)
           grandparent_node = node.parent.parent
           node.parent.begin_type? && grandparent_node.block_type? && grandparent_node.method_name == :livecheck
diff --git a/Library/Homebrew/rubocops/cask/on_system_conditionals.rb b/Library/Homebrew/rubocops/cask/on_system_conditionals.rb
index eab312a8b5..5b52af327e 100644
--- a/Library/Homebrew/rubocops/cask/on_system_conditionals.rb
+++ b/Library/Homebrew/rubocops/cask/on_system_conditionals.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 require "forwardable"
@@ -34,8 +34,9 @@ module RuboCop
 
         FLIGHT_STANZA_NAMES = [:preflight, :postflight, :uninstall_preflight, :uninstall_postflight].freeze
 
+        sig { override.params(cask_block: RuboCop::Cask::AST::CaskBlock).void }
         def on_cask(cask_block)
-          @cask_block = cask_block
+          @cask_block = T.let(cask_block, T.nilable(RuboCop::Cask::AST::CaskBlock))
 
           toplevel_stanzas.each do |stanza|
             next unless FLIGHT_STANZA_NAMES.include? stanza.stanza_name
@@ -50,10 +51,12 @@ module RuboCop
 
         private
 
+        sig { returns(T.nilable(RuboCop::Cask::AST::CaskBlock)) }
         attr_reader :cask_block
 
         def_delegators :cask_block, :toplevel_stanzas, :cask_body
 
+        sig { void }
         def simplify_sha256_stanzas
           nodes = {}
 
diff --git a/Library/Homebrew/rubocops/cask/url_legacy_comma_separators.rb b/Library/Homebrew/rubocops/cask/url_legacy_comma_separators.rb
index 3111361a50..e0afa1626f 100644
--- a/Library/Homebrew/rubocops/cask/url_legacy_comma_separators.rb
+++ b/Library/Homebrew/rubocops/cask/url_legacy_comma_separators.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 module RuboCop
@@ -12,6 +12,7 @@ module RuboCop
         MSG_CSV = "Use `version.csv.first` instead of `version.before_comma` " \
                   "and `version.csv.second` instead of `version.after_comma`."
 
+        sig { override.params(stanza: RuboCop::Cask::AST::Stanza).void }
         def on_url_stanza(stanza)
           return if stanza.stanza_node.type == :block
 
diff --git a/Library/Homebrew/rubocops/install_bundler_gems.rb b/Library/Homebrew/rubocops/install_bundler_gems.rb
index f10bf15f9d..e5f3948034 100644
--- a/Library/Homebrew/rubocops/install_bundler_gems.rb
+++ b/Library/Homebrew/rubocops/install_bundler_gems.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 module RuboCop
@@ -9,6 +9,7 @@ module RuboCop
         MSG = "Only use `Homebrew.install_bundler_gems!` in dev-cmd."
         RESTRICT_ON_SEND = [:install_bundler_gems!].freeze
 
+        sig { params(node: RuboCop::AST::Node).void }
         def on_send(node)
           file_path = processed_source.file_path
           return if file_path.match?(%r{/(dev-cmd/.+|standalone/init|startup/bootsnap)\.rb\z})
diff --git a/Library/Homebrew/rubocops/no_fileutils_rmrf.rb b/Library/Homebrew/rubocops/no_fileutils_rmrf.rb
index 7ddf6ca5ee..75aad1bb2e 100644
--- a/Library/Homebrew/rubocops/no_fileutils_rmrf.rb
+++ b/Library/Homebrew/rubocops/no_fileutils_rmrf.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 module RuboCop
@@ -30,6 +30,7 @@ module RuboCop
           (send !nil? :rmtree ...)
         PATTERN
 
+        sig { params(node: RuboCop::AST::SendNode).void }
         def on_send(node)
           return if neither_rm_rf_nor_rmtree?(node)
 
@@ -51,6 +52,7 @@ module RuboCop
           end
         end
 
+        sig { params(node: RuboCop::AST::SendNode).returns(T::Boolean) }
         def neither_rm_rf_nor_rmtree?(node)
           !any_receiver_rm_r_f?(node) && !no_receiver_rm_r_f?(node) &&
             !any_receiver_rmtree?(node) && !no_receiver_rmtree?(node)