diff --git a/UPGRADING.md b/UPGRADING.md
index 35fabfa0e..80df50303 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -31,9 +31,25 @@ We did our best to make this transition as painless as possible for you, so here
 * We've setup an [Awesome Faraday](https://github.com/lostisland/awesome-faraday) repository, where you can find and discover adapters.
   We also highlighted their unique features and level of compliance with Faraday's features.
 
+### Autoloading and dependencies
+
+Faraday has until now provided and relied on a complex dynamic dependencies system.
+This would allow to reference classes and require dependencies only when needed (e.g. when running the first request) based
+on the middleware/adapters used.
+As part of Faraday v2.0, we've removed all external dependencies, which means we don't really need this anymore.
+This change should not affect you directly, but if you're registering middleware then be aware of the new syntax:
+
+```ruby
+# `name` here can be anything you want.
+# `klass` is your custom middleware class.
+# This method can also be called on `Faraday::Adapter`, `Faraday::Request` and `Faraday::Response`
+Faraday::Middleware.register_middleware(name: klass)
+```
+
 ### Others
 
 * Rename `Faraday::Request#method` to `#http_method`.
+* Remove `Faraday::Response::Middleware`. You can now use the new `on_complete` callback provided by `Faraday::Middleware`.
 
 ## Faraday 1.0
 
diff --git a/faraday.gemspec b/faraday.gemspec
index 8350de04f..96e0669f4 100644
--- a/faraday.gemspec
+++ b/faraday.gemspec
@@ -2,7 +2,7 @@
 
 require_relative 'lib/faraday/version'
 
-Gem::Specification.new do |spec| # rubocop:disable Metrics/BlockLength
+Gem::Specification.new do |spec|
   spec.name    = 'faraday'
   spec.version = Faraday::VERSION
 
@@ -15,14 +15,7 @@ Gem::Specification.new do |spec| # rubocop:disable Metrics/BlockLength
 
   spec.required_ruby_version = '>= 2.4'
 
-  spec.add_dependency 'faraday-em_http', '~> 1.0'
-  spec.add_dependency 'faraday-em_synchrony', '~> 1.0'
-  spec.add_dependency 'faraday-excon', '~> 1.1'
-  spec.add_dependency 'faraday-httpclient', '~> 1.0.1'
   spec.add_dependency 'faraday-net_http', '~> 1.0'
-  spec.add_dependency 'faraday-net_http_persistent', '~> 1.1'
-  spec.add_dependency 'faraday-patron', '~> 1.0'
-  spec.add_dependency 'faraday-rack', '~> 1.0'
   spec.add_dependency 'multipart-post', '>= 1.2', '< 3'
   spec.add_dependency 'ruby2_keywords', '>= 0.0.4'
 
diff --git a/lib/faraday.rb b/lib/faraday.rb
index e8bd243b2..9eb7778e7 100644
--- a/lib/faraday.rb
+++ b/lib/faraday.rb
@@ -4,16 +4,10 @@
 require 'date'
 require 'set'
 require 'forwardable'
-require 'faraday/middleware_registry'
-require 'faraday/dependency_loader'
-
-unless defined?(::Faraday::Timer)
-  require 'timeout'
-  ::Faraday::Timer = Timeout
-end
-
 require 'faraday/version'
 require 'faraday/methods'
+require 'faraday/error'
+require 'faraday/middleware_registry'
 require 'faraday/utils'
 require 'faraday/options'
 require 'faraday/connection'
@@ -23,7 +17,6 @@
 require 'faraday/adapter'
 require 'faraday/request'
 require 'faraday/response'
-require 'faraday/error'
 require 'faraday/file_part'
 require 'faraday/param_part'
 
@@ -103,19 +96,6 @@ def new(url = nil, options = {}, &block)
       Faraday::Connection.new(url, options, &block)
     end
 
-    # @private
-    # Internal: Requires internal Faraday libraries.
-    #
-    # @param libs [Array] one or more relative String names to Faraday classes.
-    # @return [void]
-    def require_libs(*libs)
-      libs.each do |lib|
-        require "#{lib_path}/#{lib}"
-      end
-    end
-
-    alias require_lib require_libs
-
     # Documented elsewhere, see default_adapter reader
     def default_adapter=(adapter)
       @default_connection = nil
@@ -171,6 +151,4 @@ def method_missing(name, *args, &block)
   self.root_path = File.expand_path __dir__
   self.lib_path = File.expand_path 'faraday', __dir__
   self.default_adapter = :net_http
-
-  require_lib 'autoload' unless ENV['FARADAY_NO_AUTOLOAD']
 end
diff --git a/lib/faraday/adapter.rb b/lib/faraday/adapter.rb
index 44828c7df..f654e0358 100644
--- a/lib/faraday/adapter.rb
+++ b/lib/faraday/adapter.rb
@@ -5,14 +5,9 @@ module Faraday
   # responsible for fulfilling a Faraday request.
   class Adapter
     extend MiddlewareRegistry
-    extend DependencyLoader
 
     CONTENT_LENGTH = 'Content-Length'
 
-    register_middleware File.expand_path('adapter', __dir__),
-                        test: [:Test, 'test'],
-                        typhoeus: [:Typhoeus, 'typhoeus']
-
     # This module marks an Adapter as supporting parallel requests.
     module Parallelism
       attr_writer :supports_parallel
diff --git a/lib/faraday/adapter/test.rb b/lib/faraday/adapter/test.rb
index 41ebe06b3..12be61b00 100644
--- a/lib/faraday/adapter/test.rb
+++ b/lib/faraday/adapter/test.rb
@@ -273,3 +273,5 @@ def call(env)
     end
   end
 end
+
+Faraday::Adapter.register_middleware(test: Faraday::Adapter::Test)
diff --git a/lib/faraday/adapter/typhoeus.rb b/lib/faraday/adapter/typhoeus.rb
deleted file mode 100644
index 2f6ed6880..000000000
--- a/lib/faraday/adapter/typhoeus.rb
+++ /dev/null
@@ -1,15 +0,0 @@
-# frozen_string_literal: true
-
-module Faraday
-  class Adapter
-    # Typhoeus adapter. This class is just a stub, the real adapter is in
-    # https://github.com/typhoeus/typhoeus/blob/master/lib/typhoeus/adapters/faraday.rb
-    class Typhoeus < Faraday::Adapter
-      # Needs to define this method in order to support Typhoeus <= 1.3.0
-      def call; end
-
-      dependency 'typhoeus'
-      dependency 'typhoeus/adapters/faraday'
-    end
-  end
-end
diff --git a/lib/faraday/autoload.rb b/lib/faraday/autoload.rb
deleted file mode 100644
index 76a0e0e51..000000000
--- a/lib/faraday/autoload.rb
+++ /dev/null
@@ -1,87 +0,0 @@
-# frozen_string_literal: true
-
-module Faraday
-  # Adds the ability for other modules to manage autoloadable
-  # constants.
-  #
-  # @api private
-  module AutoloadHelper
-    # Registers the constants to be auto loaded.
-    #
-    # @param prefix [String] The require prefix. If the path is inside Faraday,
-    #           then it will be prefixed with the root path of this loaded
-    #           Faraday version.
-    # @param options [{ Symbol => String }] library names.
-    #
-    # @example
-    #
-    #   Faraday.autoload_all 'faraday/foo',
-    #     Bar: 'bar'
-    #
-    #   # requires faraday/foo/bar to load Faraday::Bar.
-    #   Faraday::Bar
-    #
-    # @return [void]
-    def autoload_all(prefix, options)
-      if prefix.match? %r{^faraday(/|$)}i
-        prefix = File.join(Faraday.root_path, prefix)
-      end
-
-      options.each do |const_name, path|
-        autoload const_name, File.join(prefix, path)
-      end
-    end
-
-    # Loads each autoloaded constant.  If thread safety is a concern,
-    # wrap this in a Mutex.
-    #
-    # @return [void]
-    def load_autoloaded_constants
-      constants.each do |const|
-        const_get(const) if autoload?(const)
-      end
-    end
-
-    # Filters the module's contents with those that have been already
-    # autoloaded.
-    #
-    # @return [Array<Class, Module>]
-    def all_loaded_constants
-      constants
-        .map { |c| const_get(c) }
-        .select { |a| a.respond_to?(:loaded?) && a.loaded? }
-    end
-  end
-
-  # Adapter is the base class for all Faraday adapters.
-  # @see lib/faraday/adapter.rb Original class location
-  class Adapter
-    extend AutoloadHelper
-    autoload_all 'faraday/adapter',
-                 Typhoeus: 'typhoeus',
-                 Test: 'test'
-  end
-
-  # Request represents a single HTTP request for a Faraday adapter to make.
-  # @see lib/faraday/request.rb Original class location
-  class Request
-    extend AutoloadHelper
-    autoload_all 'faraday/request',
-                 UrlEncoded: 'url_encoded',
-                 Multipart: 'multipart',
-                 Retry: 'retry',
-                 Authorization: 'authorization',
-                 BasicAuthentication: 'basic_authentication',
-                 TokenAuthentication: 'token_authentication',
-                 Instrumentation: 'instrumentation'
-  end
-
-  # Response represents the returned value of a sent Faraday request.
-  # @see lib/faraday/response.rb Original class location
-  class Response
-    extend AutoloadHelper
-    autoload_all 'faraday/response',
-                 RaiseError: 'raise_error',
-                 Logger: 'logger'
-  end
-end
diff --git a/lib/faraday/dependency_loader.rb b/lib/faraday/dependency_loader.rb
deleted file mode 100644
index 57345646d..000000000
--- a/lib/faraday/dependency_loader.rb
+++ /dev/null
@@ -1,37 +0,0 @@
-# frozen_string_literal: true
-
-module Faraday
-  # DependencyLoader helps Faraday adapters and middleware load dependencies.
-  module DependencyLoader
-    attr_reader :load_error
-
-    # Executes a block which should try to require and reference dependent
-    # libraries
-    def dependency(lib = nil)
-      lib ? require(lib) : yield
-    rescue LoadError, NameError => e
-      self.load_error = e
-    end
-
-    def new(*)
-      unless loaded?
-        raise "missing dependency for #{self}: #{load_error.message}"
-      end
-
-      super
-    end
-
-    def loaded?
-      load_error.nil?
-    end
-
-    def inherited(subclass)
-      super
-      subclass.send(:load_error=, load_error)
-    end
-
-    private
-
-    attr_writer :load_error
-  end
-end
diff --git a/lib/faraday/logging/formatter.rb b/lib/faraday/logging/formatter.rb
index ba3e49765..dc3c03663 100644
--- a/lib/faraday/logging/formatter.rb
+++ b/lib/faraday/logging/formatter.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'pp'
+
 module Faraday
   module Logging
     # Serves as an integration point to customize logging
diff --git a/lib/faraday/middleware.rb b/lib/faraday/middleware.rb
index fcf9f4fa0..c6e236f20 100644
--- a/lib/faraday/middleware.rb
+++ b/lib/faraday/middleware.rb
@@ -4,7 +4,6 @@ module Faraday
   # Middleware is the basic base class of any Faraday middleware.
   class Middleware
     extend MiddlewareRegistry
-    extend DependencyLoader
 
     attr_reader :app, :options
 
diff --git a/lib/faraday/middleware_registry.rb b/lib/faraday/middleware_registry.rb
index 021038fec..96fe0deb9 100644
--- a/lib/faraday/middleware_registry.rb
+++ b/lib/faraday/middleware_registry.rb
@@ -6,59 +6,26 @@ module Faraday
   # Adds the ability for other modules to register and lookup
   # middleware classes.
   module MiddlewareRegistry
+    def registered_middleware
+      @registered_middleware ||= {}
+    end
+
     # Register middleware class(es) on the current module.
     #
-    # @param autoload_path [String] Middleware autoload path
-    # @param mapping [Hash{
-    #          Symbol => Module,
-    #          Symbol => Array<Module, Symbol, String>,
-    #        }] Middleware mapping from a lookup symbol to a reference to the
-    #        middleware.
-    #        Classes can be expressed as:
-    #          - a fully qualified constant
-    #          - a Symbol
-    #          - a Proc that will be lazily called to return the former
-    #          - an array is given, its first element is the constant or symbol,
-    #            and its second is a file to `require`.
+    # @param mappings [Hash] Middleware mappings from a lookup symbol to a middleware class.
     # @return [void]
     #
     # @example Lookup by a constant
     #
     #   module Faraday
-    #     class Whatever
+    #     class Whatever < Middleware
     #       # Middleware looked up by :foo returns Faraday::Whatever::Foo.
-    #       register_middleware foo: Foo
-    #     end
-    #   end
-    #
-    # @example Lookup by a symbol
-    #
-    #   module Faraday
-    #     class Whatever
-    #       # Middleware looked up by :bar returns
-    #       # Faraday::Whatever.const_get(:Bar)
-    #       register_middleware bar: :Bar
-    #     end
-    #   end
-    #
-    # @example Lookup by a symbol and string in an array
-    #
-    #   module Faraday
-    #     class Whatever
-    #       # Middleware looked up by :baz requires 'baz' and returns
-    #       # Faraday::Whatever.const_get(:Baz)
-    #       register_middleware baz: [:Baz, 'baz']
+    #       register_middleware(foo: Whatever)
     #     end
     #   end
-    #
-    def register_middleware(autoload_path = nil, mapping = nil)
-      if mapping.nil?
-        mapping = autoload_path
-        autoload_path = nil
-      end
+    def register_middleware(**mappings)
       middleware_mutex do
-        @middleware_autoload_path = autoload_path if autoload_path
-        (@registered_middleware ||= {}).update(mapping)
+        registered_middleware.update(mappings)
       end
     end
 
@@ -66,7 +33,7 @@ def register_middleware(autoload_path = nil, mapping = nil)
     #
     # @param key [Symbol] key for the registered middleware.
     def unregister_middleware(key)
-      @registered_middleware.delete(key)
+      registered_middleware.delete(key)
     end
 
     # Lookup middleware class with a registered Symbol shortcut.
@@ -78,16 +45,15 @@ def unregister_middleware(key)
     # @example
     #
     #   module Faraday
-    #     class Whatever
-    #       register_middleware foo: Foo
+    #     class Whatever < Middleware
+    #       register_middleware(foo: Whatever)
     #     end
     #   end
     #
-    #   Faraday::Whatever.lookup_middleware(:foo)
-    #   # => Faraday::Whatever::Foo
-    #
+    #   Faraday::Middleware.lookup_middleware(:foo)
+    #   # => Faraday::Whatever
     def lookup_middleware(key)
-      load_middleware(key) ||
+      registered_middleware[key] ||
         raise(Faraday::Error, "#{key.inspect} is not registered on #{self}")
     end
 
@@ -95,35 +61,5 @@ def middleware_mutex(&block)
       @middleware_mutex ||= Monitor.new
       @middleware_mutex.synchronize(&block)
     end
-
-    def fetch_middleware(key)
-      defined?(@registered_middleware) && @registered_middleware[key]
-    end
-
-    def load_middleware(key)
-      value = fetch_middleware(key)
-      case value
-      when Module
-        value
-      when Symbol, String
-        middleware_mutex do
-          @registered_middleware[key] = const_get(value)
-        end
-      when Proc
-        middleware_mutex do
-          @registered_middleware[key] = value.call
-        end
-      when Array
-        middleware_mutex do
-          const, path = value
-          if (root = @middleware_autoload_path)
-            path = "#{root}/#{path}"
-          end
-          require(path)
-          @registered_middleware[key] = const
-        end
-        load_middleware(key)
-      end
-    end
   end
 end
diff --git a/lib/faraday/request.rb b/lib/faraday/request.rb
index f709bc403..e2c45948c 100644
--- a/lib/faraday/request.rb
+++ b/lib/faraday/request.rb
@@ -26,29 +26,11 @@ module Faraday
   #   @return [RequestOptions] options
   #
   # rubocop:disable Style/StructInheritance
-  class Request < Struct.new(
-    :http_method, :path, :params, :headers, :body, :options
-  )
+  class Request < Struct.new(:http_method, :path, :params, :headers, :body, :options)
     # rubocop:enable Style/StructInheritance
 
     extend MiddlewareRegistry
 
-    register_middleware File.expand_path('request', __dir__),
-                        url_encoded: [:UrlEncoded, 'url_encoded'],
-                        multipart: [:Multipart, 'multipart'],
-                        retry: [:Retry, 'retry'],
-                        authorization: [:Authorization, 'authorization'],
-                        basic_auth: [
-                          :BasicAuthentication,
-                          'basic_authentication'
-                        ],
-                        token_auth: [
-                          :TokenAuthentication,
-                          'token_authentication'
-                        ],
-                        instrumentation: [:Instrumentation, 'instrumentation'],
-                        json: [:Json, 'json']
-
     # @param request_method [String]
     # @yield [request] for block customization, if block given
     # @yieldparam request [Request]
@@ -155,3 +137,11 @@ def to_env(connection)
     end
   end
 end
+
+require 'faraday/request/authorization'
+require 'faraday/request/basic_authentication'
+require 'faraday/request/instrumentation'
+require 'faraday/request/multipart'
+require 'faraday/request/retry'
+require 'faraday/request/token_authentication'
+require 'faraday/request/url_encoded'
diff --git a/lib/faraday/request/authorization.rb b/lib/faraday/request/authorization.rb
index f9b56c871..c6d7d540b 100644
--- a/lib/faraday/request/authorization.rb
+++ b/lib/faraday/request/authorization.rb
@@ -4,9 +4,7 @@ module Faraday
   class Request
     # Request middleware for the Authorization HTTP header
     class Authorization < Faraday::Middleware
-      unless defined?(::Faraday::Request::Authorization::KEY)
-        KEY = 'Authorization'
-      end
+      KEY = 'Authorization'
 
       # @param type [String, Symbol]
       # @param token [String, Symbol, Hash]
@@ -53,3 +51,5 @@ def call(env)
     end
   end
 end
+
+Faraday::Request.register_middleware(authorization: Faraday::Request::Authorization)
diff --git a/lib/faraday/request/basic_authentication.rb b/lib/faraday/request/basic_authentication.rb
index 61c9a5bc3..f1d1ee8f5 100644
--- a/lib/faraday/request/basic_authentication.rb
+++ b/lib/faraday/request/basic_authentication.rb
@@ -1,11 +1,12 @@
 # frozen_string_literal: true
 
 require 'base64'
+require 'faraday/request/authorization'
 
 module Faraday
   class Request
     # Authorization middleware for Basic Authentication.
-    class BasicAuthentication < load_middleware(:authorization)
+    class BasicAuthentication < Authorization
       # @param login [String]
       # @param pass [String]
       #
@@ -18,3 +19,5 @@ def self.header(login, pass)
     end
   end
 end
+
+Faraday::Request.register_middleware(basic_auth: Faraday::Request::BasicAuthentication)
diff --git a/lib/faraday/request/instrumentation.rb b/lib/faraday/request/instrumentation.rb
index a24442f3a..c03ba1e52 100644
--- a/lib/faraday/request/instrumentation.rb
+++ b/lib/faraday/request/instrumentation.rb
@@ -52,3 +52,5 @@ def call(env)
     end
   end
 end
+
+Faraday::Request.register_middleware(instrumentation: Faraday::Request::Instrumentation)
diff --git a/lib/faraday/request/multipart.rb b/lib/faraday/request/multipart.rb
index 1f96c8d96..64b2f2526 100644
--- a/lib/faraday/request/multipart.rb
+++ b/lib/faraday/request/multipart.rb
@@ -104,3 +104,5 @@ def process_params(params, prefix = nil, pieces = nil, &block)
     end
   end
 end
+
+Faraday::Request.register_middleware(multipart: Faraday::Request::Multipart)
diff --git a/lib/faraday/request/retry.rb b/lib/faraday/request/retry.rb
index 312af1c8d..3ba50b7a0 100644
--- a/lib/faraday/request/retry.rb
+++ b/lib/faraday/request/retry.rb
@@ -237,3 +237,5 @@ def calculate_retry_interval(retries)
     end
   end
 end
+
+Faraday::Request.register_middleware(retry: Faraday::Request::Retry)
diff --git a/lib/faraday/request/token_authentication.rb b/lib/faraday/request/token_authentication.rb
index f28264b1c..7418c8efe 100644
--- a/lib/faraday/request/token_authentication.rb
+++ b/lib/faraday/request/token_authentication.rb
@@ -1,10 +1,12 @@
 # frozen_string_literal: true
 
+require 'faraday/request/authorization'
+
 module Faraday
   class Request
     # TokenAuthentication is a middleware that adds a 'Token' header to a
     # Faraday request.
-    class TokenAuthentication < load_middleware(:authorization)
+    class TokenAuthentication < Authorization
       # Public
       def self.header(token, options = nil)
         options ||= {}
@@ -18,3 +20,5 @@ def initialize(app, token, options = nil)
     end
   end
 end
+
+Faraday::Request.register_middleware(token_auth: Faraday::Request::TokenAuthentication)
diff --git a/lib/faraday/request/url_encoded.rb b/lib/faraday/request/url_encoded.rb
index 00cc973dd..77aa44f8d 100644
--- a/lib/faraday/request/url_encoded.rb
+++ b/lib/faraday/request/url_encoded.rb
@@ -54,3 +54,5 @@ def request_type(env)
     end
   end
 end
+
+Faraday::Request.register_middleware(url_encoded: Faraday::Request::UrlEncoded)
diff --git a/lib/faraday/response.rb b/lib/faraday/response.rb
index d58869849..187525a4b 100644
--- a/lib/faraday/response.rb
+++ b/lib/faraday/response.rb
@@ -5,26 +5,9 @@
 module Faraday
   # Response represents an HTTP response from making an HTTP request.
   class Response
-    # Used for simple response middleware.
-    class Middleware < Faraday::Middleware
-      # Override this to modify the environment after the response has finished.
-      # Calls the `parse` method if defined
-      # `parse` method can be defined as private, public and protected
-      def on_complete(env)
-        return unless respond_to?(:parse, true) && env.parse_body?
-
-        env.body = parse(env.body)
-      end
-    end
-
     extend Forwardable
     extend MiddlewareRegistry
 
-    register_middleware File.expand_path('response', __dir__),
-                        raise_error: [:RaiseError, 'raise_error'],
-                        logger: [:Logger, 'logger'],
-                        json: [:Json, 'json']
-
     def initialize(env = nil)
       @env = Env.from(env) if env
       @on_complete_callbacks = []
@@ -101,3 +84,6 @@ def apply_request(request_env)
     end
   end
 end
+
+require 'faraday/response/logger'
+require 'faraday/response/raise_error'
diff --git a/lib/faraday/response/logger.rb b/lib/faraday/response/logger.rb
index 2ad458716..387ce335c 100644
--- a/lib/faraday/response/logger.rb
+++ b/lib/faraday/response/logger.rb
@@ -29,3 +29,5 @@ def on_complete(env)
     end
   end
 end
+
+Faraday::Response.register_middleware(logger: Faraday::Response::Logger)
diff --git a/lib/faraday/response/raise_error.rb b/lib/faraday/response/raise_error.rb
index 467f3cd18..9e27d90ad 100644
--- a/lib/faraday/response/raise_error.rb
+++ b/lib/faraday/response/raise_error.rb
@@ -54,3 +54,5 @@ def response_values(env)
     end
   end
 end
+
+Faraday::Response.register_middleware(raise_error: Faraday::Response::RaiseError)
diff --git a/lib/faraday/utils.rb b/lib/faraday/utils.rb
index b052f9b2f..db37d66d9 100644
--- a/lib/faraday/utils.rb
+++ b/lib/faraday/utils.rb
@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require 'uri'
 require 'faraday/utils/headers'
 require 'faraday/utils/params_hash'
 
@@ -71,10 +72,7 @@ def URI(url) # rubocop:disable Naming/MethodName
     end
 
     def default_uri_parser
-      @default_uri_parser ||= begin
-        require 'uri'
-        Kernel.method(:URI)
-      end
+      @default_uri_parser ||= Kernel.method(:URI)
     end
 
     def default_uri_parser=(parser)
diff --git a/spec/faraday/rack_builder_spec.rb b/spec/faraday/rack_builder_spec.rb
index aa28564c5..e00691673 100644
--- a/spec/faraday/rack_builder_spec.rb
+++ b/spec/faraday/rack_builder_spec.rb
@@ -17,10 +17,6 @@ class Orange < Handler
   class Banana < Handler
   end
 
-  class Broken < Faraday::Middleware
-    dependency 'zomg/i_dont/exist'
-  end
-
   subject { conn.builder }
 
   context 'with default stack' do
@@ -127,24 +123,6 @@ class Broken < Faraday::Middleware
       subject.use(:apple)
       expect(subject.handlers).to eq([Apple])
     end
-
-    it 'allows to register with symbol' do
-      Faraday::Middleware.register_middleware(apple: :Apple)
-      subject.use(:apple)
-      expect(subject.handlers).to eq([Apple])
-    end
-
-    it 'allows to register with string' do
-      Faraday::Middleware.register_middleware(apple: 'Apple')
-      subject.use(:apple)
-      expect(subject.handlers).to eq([Apple])
-    end
-
-    it 'allows to register with Proc' do
-      Faraday::Middleware.register_middleware(apple: -> { Apple })
-      subject.use(:apple)
-      expect(subject.handlers).to eq([Apple])
-    end
   end
 
   context 'when having two handlers' do
@@ -176,24 +154,6 @@ class Broken < Faraday::Middleware
     end
   end
 
-  context 'when having a handler with broken dependency' do
-    let(:conn) do
-      Faraday::Connection.new do |builder|
-        builder.adapter :test do |stub|
-          stub.get('/') { |_| [200, {}, ''] }
-        end
-      end
-    end
-
-    before { subject.use(Broken) }
-
-    it 'raises an error while making a request' do
-      expect { conn.get('/') }.to raise_error(RuntimeError) do |err|
-        expect(err.message).to match(%r{missing dependency for Broken: .+ -- zomg/i_dont/exist})
-      end
-    end
-  end
-
   context 'when middleware is added with named arguments' do
     let(:conn) { Faraday::Connection.new {} }
 
@@ -220,7 +180,7 @@ def initialize(app, name:)
     end
   end
 
-  context 'when a request adapter is added with named arguments' do
+  context 'when a middleware is added with named arguments' do
     let(:conn) { Faraday::Connection.new {} }
 
     let(:cat_request) do
@@ -247,11 +207,11 @@ def initialize(app, name:)
     end
   end
 
-  context 'when a response adapter is added with named arguments' do
+  context 'when a middleware is added with named arguments' do
     let(:conn) { Faraday::Connection.new {} }
 
     let(:fish_response) do
-      Class.new(Faraday::Response::Middleware) do
+      Class.new(Faraday::Middleware) do
         attr_accessor :name
 
         def initialize(app, name:)
diff --git a/spec/faraday/response/middleware_spec.rb b/spec/faraday/response/middleware_spec.rb
deleted file mode 100644
index a79208c4b..000000000
--- a/spec/faraday/response/middleware_spec.rb
+++ /dev/null
@@ -1,68 +0,0 @@
-# frozen_string_literal: true
-
-RSpec.describe Faraday::Response::Middleware do
-  let(:conn) do
-    Faraday.new do |b|
-      b.use custom_middleware
-      b.adapter :test do |stub|
-        stub.get('ok') { [200, { 'Content-Type' => 'text/html' }, '<body></body>'] }
-        stub.get('not_modified') { [304, nil, nil] }
-        stub.get('no_content') { [204, nil, nil] }
-      end
-    end
-  end
-
-  context 'with a custom ResponseMiddleware' do
-    let(:custom_middleware) do
-      Class.new(Faraday::Response::Middleware) do
-        def parse(body)
-          body.upcase
-        end
-      end
-    end
-
-    it 'parses the response' do
-      expect(conn.get('ok').body).to eq('<BODY></BODY>')
-    end
-  end
-
-  context 'with a custom ResponseMiddleware and private parse' do
-    let(:custom_middleware) do
-      Class.new(Faraday::Response::Middleware) do
-        private
-
-        def parse(body)
-          body.upcase
-        end
-      end
-    end
-
-    it 'parses the response' do
-      expect(conn.get('ok').body).to eq('<BODY></BODY>')
-    end
-  end
-
-  context 'with a custom ResponseMiddleware but empty response' do
-    let(:custom_middleware) do
-      Class.new(Faraday::Response::Middleware) do
-        def parse(_body)
-          raise 'this should not be called'
-        end
-      end
-    end
-
-    it 'raises exception for 200 responses' do
-      expect { conn.get('ok') }.to raise_error(StandardError)
-    end
-
-    it 'doesn\'t call the middleware for 204 responses' do
-      expect_any_instance_of(custom_middleware).not_to receive(:parse)
-      expect(conn.get('no_content').body).to be_nil
-    end
-
-    it 'doesn\'t call the middleware for 304 responses' do
-      expect_any_instance_of(custom_middleware).not_to receive(:parse)
-      expect(conn.get('not_modified').body).to be_nil
-    end
-  end
-end