diff --git a/Library/Homebrew/api/cask.rb b/Library/Homebrew/api/cask.rb
index 17ca86b716..8d0274cda8 100644
--- a/Library/Homebrew/api/cask.rb
+++ b/Library/Homebrew/api/cask.rb
@@ -10,9 +10,9 @@ module Homebrew
     #
     # @api private
     module Cask
-      class << self
-        include Cachable
+      extend Cachable
 
+      class << self
         private :cache
 
         sig { params(token: String).returns(Hash) }
diff --git a/Library/Homebrew/api/formula.rb b/Library/Homebrew/api/formula.rb
index 8704ec6ad4..ba5a1de330 100644
--- a/Library/Homebrew/api/formula.rb
+++ b/Library/Homebrew/api/formula.rb
@@ -10,9 +10,9 @@ module Homebrew
     #
     # @api private
     module Formula
-      class << self
-        include Cachable
+      extend Cachable
 
+      class << self
         private :cache
 
         sig { params(name: String).returns(Hash) }
diff --git a/Library/Homebrew/extend/cachable.rb b/Library/Homebrew/extend/cachable.rb
index b124c638e6..9c65e1bc36 100644
--- a/Library/Homebrew/extend/cachable.rb
+++ b/Library/Homebrew/extend/cachable.rb
@@ -1,4 +1,4 @@
-# typed: strict
+# typed: true
 # frozen_string_literal: true
 
 module Cachable
@@ -11,4 +11,43 @@ module Cachable
   def clear_cache
     cache.clear
   end
+
+  # Collect all classes that mix in Cachable so that those caches can be cleared in-between tests.
+  if ENV["HOMEBREW_TESTS"]
+    def self.included(klass)
+      raise ArgumentError, "Don't use Cachable with singleton classes" if klass.singleton_class?
+
+      super if defined?(super)
+    end
+
+    # Ignore classes that get inherited from a lot and that have
+    # caches that we don't need to clear on the class level.
+    IGNORE_INHERITED_CLASSES = %w[Formula Cask].freeze
+    private_constant :IGNORE_INHERITED_CLASSES
+
+    def self.extended(klass)
+      Registry.list << klass
+      klass.extend(Inherited) unless IGNORE_INHERITED_CLASSES.include?(klass.name)
+      super if defined?(super)
+    end
+
+    module Inherited
+      def inherited(klass)
+        # A class might inherit Cachable at the instance level
+        # and in that case we just want to skip registering it.
+        Registry.list << klass if klass.respond_to?(:clear_cache)
+        super if defined?(super)
+      end
+    end
+
+    module Registry
+      def self.list
+        @list ||= []
+      end
+
+      def self.clear_all_caches
+        list.each(&:clear_cache)
+      end
+    end
+  end
 end
diff --git a/Library/Homebrew/readall.rb b/Library/Homebrew/readall.rb
index 91407529aa..778b10ca65 100644
--- a/Library/Homebrew/readall.rb
+++ b/Library/Homebrew/readall.rb
@@ -9,8 +9,9 @@ require "system_command"
 #
 # @api private
 module Readall
+  extend Cachable
+
   class << self
-    include Cachable
     include SystemCommand::Mixin
 
     # TODO: remove this once the `MacOS` module is undefined on Linux
diff --git a/Library/Homebrew/test/spec_helper.rb b/Library/Homebrew/test/spec_helper.rb
index 9d2f2d10ee..f9ed707426 100644
--- a/Library/Homebrew/test/spec_helper.rb
+++ b/Library/Homebrew/test/spec_helper.rb
@@ -202,16 +202,7 @@ RSpec.configure do |config|
   config.around do |example|
     Homebrew.raise_deprecation_exceptions = true
 
-    Formulary.clear_cache
-    Tap.each(&:clear_cache)
-    Tap.clear_cache
-    DependencyCollector.clear_cache
-    Formula.clear_cache
-    Keg.clear_cache
-    Tab.clear_cache
-    Dependency.clear_cache
-    Requirement.clear_cache
-    Readall.clear_cache if defined?(Readall)
+    Cachable::Registry.clear_all_caches
     FormulaInstaller.clear_attempted
     FormulaInstaller.clear_installed
     FormulaInstaller.clear_fetched
@@ -263,15 +254,7 @@ RSpec.configure do |config|
       @__stderr.close
       @__stdin.close
 
-      Formulary.clear_cache
-      Tap.clear_cache
-      DependencyCollector.clear_cache
-      Formula.clear_cache
-      Keg.clear_cache
-      Tab.clear_cache
-      Dependency.clear_cache
-      Requirement.clear_cache
-      Readall.clear_cache if defined?(Readall)
+      Cachable::Registry.clear_all_caches
 
       FileUtils.rm_rf [
         *TEST_DIRECTORIES,