diff --git a/Library/Homebrew/cask/url.rb b/Library/Homebrew/cask/url.rb
index 47af7f7079..7efafb5a95 100644
--- a/Library/Homebrew/cask/url.rb
+++ b/Library/Homebrew/cask/url.rb
@@ -5,12 +5,12 @@ require "source_location"
 require "utils/curl"
 
 module Cask
-  BlockReturn = T.type_alias do
-    T.any(URI::Generic, String, [T.any(URI::Generic, String), T::Hash[Symbol, T.untyped]])
-  end
-
   # Class corresponding to the `url` stanza.
   class URL < SimpleDelegator
+    BlockReturn = T.type_alias do
+      T.any(URI::Generic, String, [T.any(URI::Generic, String), T::Hash[Symbol, T.untyped]])
+    end
+
     class DSL
       sig { returns(T.any(URI::Generic, String)) }
       attr_reader :uri
@@ -173,9 +173,8 @@ module Cask
       #
       # @api public
       sig {
-        override
-          .params(method: Symbol, args: T.untyped, block: T.nilable(T.proc.returns(T.untyped)))
-          .returns(T.untyped)
+        override.params(method: Symbol, args: T.untyped, block: T.nilable(T.proc.returns(T.untyped)))
+                .returns(T.anything)
       }
       def method_missing(method, *args, &block)
         if @dsl.respond_to?(method)
diff --git a/Library/Homebrew/dev-cmd/create.rb b/Library/Homebrew/dev-cmd/create.rb
index 6c5414f2d4..830d995c8f 100644
--- a/Library/Homebrew/dev-cmd/create.rb
+++ b/Library/Homebrew/dev-cmd/create.rb
@@ -115,7 +115,7 @@ module Homebrew
             strategy = DownloadStrategyDetector.detect(url)
             downloader = strategy.new(url, token, version.to_s, cache: Cask::Cache.path)
             downloader.fetch
-            downloader.cached_location!.sha256
+            downloader.cached_location.sha256
           end
 
           [url.gsub(version.to_s, "\#{version}"), sha256]
diff --git a/Library/Homebrew/download_strategy.rb b/Library/Homebrew/download_strategy.rb
index ef3c3548a9..887c25f86f 100644
--- a/Library/Homebrew/download_strategy.rb
+++ b/Library/Homebrew/download_strategy.rb
@@ -50,12 +50,6 @@ class AbstractDownloadStrategy
   sig { returns(String) }
   attr_reader :url
 
-  # Location of the cached download.
-  #
-  # @api public
-  sig { returns(T.nilable(Pathname)) }
-  attr_reader :cached_location
-
   sig { returns(Pathname) }
   attr_reader :cache
 
@@ -90,8 +84,11 @@ class AbstractDownloadStrategy
   sig { overridable.params(timeout: T.any(Float, Integer, NilClass)).void }
   def fetch(timeout: nil); end
 
-  sig { returns(Pathname) }
-  def cached_location! = T.must(cached_location)
+  # Location of the cached download.
+  #
+  # @api public
+  sig { abstract.returns(Pathname) }
+  def cached_location; end
 
   # Disable any output during downloading.
   #
@@ -117,7 +114,7 @@ class AbstractDownloadStrategy
   # @api public
   sig { overridable.params(block: T.untyped).void }
   def stage(&block)
-    UnpackStrategy.detect(cached_location!,
+    UnpackStrategy.detect(cached_location,
                           prioritize_extension: true,
                           ref_type: @ref_type, ref: @ref)
                   .extract_nestedly(basename:,
@@ -158,12 +155,12 @@ class AbstractDownloadStrategy
   # @api public
   sig { overridable.void }
   def clear_cache
-    rm_rf(cached_location!)
+    rm_rf(cached_location)
   end
 
   sig { returns(Pathname) }
   def basename
-    cached_location!.basename
+    cached_location.basename
   end
 
   private
@@ -212,7 +209,7 @@ end
 class VCSDownloadStrategy < AbstractDownloadStrategy
   abstract!
 
-  sig { returns(Pathname) }
+  sig { override.returns(Pathname) }
   attr_reader :cached_location
 
   REF_TYPES = [:tag, :branch, :revisions, :revision].freeze
@@ -336,7 +333,7 @@ class AbstractFileDownloadStrategy < AbstractDownloadStrategy
   # Path for storing the completed download.
   #
   # @api public
-  sig { returns(Pathname) }
+  sig { override.returns(Pathname) }
   def cached_location
     return @cached_location if @cached_location
 
diff --git a/Library/Homebrew/downloadable.rb b/Library/Homebrew/downloadable.rb
index 3f917e983b..037e9ad0d6 100644
--- a/Library/Homebrew/downloadable.rb
+++ b/Library/Homebrew/downloadable.rb
@@ -56,7 +56,7 @@ module Downloadable
 
   sig { overridable.returns(Pathname) }
   def cached_download
-    downloader.cached_location!
+    downloader.cached_location
   end
 
   sig { overridable.void }
diff --git a/Library/Homebrew/test/cask/tab_spec.rb b/Library/Homebrew/test/cask/tab_spec.rb
index 9b346e2601..be2f5bdc25 100644
--- a/Library/Homebrew/test/cask/tab_spec.rb
+++ b/Library/Homebrew/test/cask/tab_spec.rb
@@ -124,8 +124,10 @@ RSpec.describe Cask::Tab, :cask do
     specify "with all types of dependencies" do
       cask = Cask::CaskLoader.load("with-depends-on-everything")
 
-      unar = instance_double(Formula, full_name: "unar", version: "1.2", revision: 0, pkg_version: "1.2",
-                             deps: [], requirements: [])
+      unar = Class.new(Formula) do
+        url "my_url"
+        version "1.2"
+      end.new("unar", Pathname.new(__FILE__).expand_path, :stable)
       expect(Formulary).to receive(:factory).with("unar").and_return(unar)
 
       expected_hash = {
diff --git a/Library/Homebrew/utils/topological_hash.rb b/Library/Homebrew/utils/topological_hash.rb
index 9b6cec4f20..14e1bd705b 100644
--- a/Library/Homebrew/utils/topological_hash.rb
+++ b/Library/Homebrew/utils/topological_hash.rb
@@ -27,14 +27,15 @@ module Utils
       packages.each do |cask_or_formula|
         next if accumulator.key?(cask_or_formula)
 
-        if cask_or_formula.is_a?(Cask::Cask)
+        case cask_or_formula
+        when Cask::Cask
           formula_deps = cask_or_formula.depends_on
                                         .formula
                                         .map { |f| Formula[f] }
           cask_deps = cask_or_formula.depends_on
                                      .cask
                                      .map { |c| Cask::CaskLoader.load(c, config: nil) }
-        else
+        when Formula
           formula_deps = cask_or_formula.deps
                                         .reject(&:build?)
                                         .reject(&:test?)
@@ -42,6 +43,8 @@ module Utils
           cask_deps = cask_or_formula.requirements
                                      .filter_map(&:cask)
                                      .map { |c| Cask::CaskLoader.load(c, config: nil) }
+        else
+          T.absurd(cask_or_formula)
         end
 
         accumulator[cask_or_formula] = formula_deps + cask_deps