diff --git a/benchmarks/local/puma_info.rb b/benchmarks/local/puma_info.rb
index adfd346d98..5a4c7d7efa 100644
--- a/benchmarks/local/puma_info.rb
+++ b/benchmarks/local/puma_info.rb
@@ -90,7 +90,7 @@ def initialize(argv, stdout=STDOUT, stderr=STDERR)
 
         if @config_file
           config = Puma::Configuration.new({ config_files: [@config_file] }, {})
-          config.load
+          config.clamp
           @state              ||= config.options[:state]
           @control_url        ||= config.options[:control_url]
           @control_auth_token ||= config.options[:control_auth_token]
diff --git a/lib/puma/binder.rb b/lib/puma/binder.rb
index 44e923ff7d..34f444e7bd 100644
--- a/lib/puma/binder.rb
+++ b/lib/puma/binder.rb
@@ -5,7 +5,6 @@
 
 require_relative 'const'
 require_relative 'util'
-require_relative 'configuration'
 
 module Puma
 
@@ -19,9 +18,9 @@ class Binder
 
     RACK_VERSION = [1,6].freeze
 
-    def initialize(log_writer, conf = Configuration.new, env: ENV)
+    def initialize(log_writer, options, env: ENV)
       @log_writer = log_writer
-      @conf = conf
+      @options = options
       @listeners = []
       @inherited_fds = {}
       @activated_sockets = {}
@@ -31,10 +30,10 @@ def initialize(log_writer, conf = Configuration.new, env: ENV)
       @proto_env = {
         "rack.version".freeze => RACK_VERSION,
         "rack.errors".freeze => log_writer.stderr,
-        "rack.multithread".freeze => conf.options[:max_threads] > 1,
-        "rack.multiprocess".freeze => conf.options[:workers] >= 1,
+        "rack.multithread".freeze => options[:max_threads] > 1,
+        "rack.multiprocess".freeze => options[:workers] >= 1,
         "rack.run_once".freeze => false,
-        RACK_URL_SCHEME => conf.options[:rack_url_scheme],
+        RACK_URL_SCHEME => options[:rack_url_scheme],
         "SCRIPT_NAME".freeze => env['SCRIPT_NAME'] || "",
 
         # I'd like to set a default CONTENT_TYPE here but some things
@@ -246,7 +245,7 @@ def parse(binds, log_writer = nil, log_msg = 'Listening')
               cert_key.each do |v|
                 if params[v]&.start_with?('store:')
                   index = Integer(params.delete(v).split('store:').last)
-                  params["#{v}_pem"] = @conf.options[:store][index]
+                  params["#{v}_pem"] = @options[:store][index]
                 end
               end
               MiniSSL::ContextBuilder.new(params, @log_writer).context
diff --git a/lib/puma/cli.rb b/lib/puma/cli.rb
index 8f0c7a8f27..20dfb325cc 100644
--- a/lib/puma/cli.rb
+++ b/lib/puma/cli.rb
@@ -93,7 +93,7 @@ def configure_control_url(command_line_arg)
     #
 
     def setup_options(env = ENV)
-      @conf = Configuration.new({}, {events: @events}, env) do |user_config, file_config|
+      @conf = Configuration.new({}, { events: @events }, env) do |user_config, file_config|
         @parser = OptionParser.new do |o|
           o.on "-b", "--bind URI", "URI to bind to (tcp://, unix://, ssl://)" do |arg|
             user_config.bind arg
diff --git a/lib/puma/configuration.rb b/lib/puma/configuration.rb
index 73d7660d23..7ce2b5b710 100644
--- a/lib/puma/configuration.rb
+++ b/lib/puma/configuration.rb
@@ -3,6 +3,7 @@
 require_relative 'plugin'
 require_relative 'const'
 require_relative 'dsl'
+require_relative 'events'
 
 module Puma
   # A class used for storing "leveled" configuration options.
@@ -112,7 +113,7 @@ def final_options
   #     config = Configuration.new({}) do |user_config, file_config, default_config|
   #       user_config.port 3003
   #     end
-  #     config.load
+  #     config.clamp
   #     puts config.options[:port]
   #     # => 3003
   #
@@ -125,6 +126,9 @@ def final_options
   # is done because an environment variable may have been modified while loading
   # configuration files.
   class Configuration
+    class NotLoadedError < StandardError; end
+    class NotClampedError < StandardError; end
+
     DEFAULTS = {
       auto_trim_time: 30,
       binds: ['tcp://0.0.0.0:9292'.freeze],
@@ -174,14 +178,16 @@ class Configuration
     def initialize(user_options={}, default_options = {}, env = ENV, &block)
       default_options = self.puma_default_options(env).merge(default_options)
 
-      @options     = UserFileDefaultOptions.new(user_options, default_options)
+      @_options    = UserFileDefaultOptions.new(user_options, default_options)
       @plugins     = PluginLoader.new
-      @user_dsl    = DSL.new(@options.user_options, self)
-      @file_dsl    = DSL.new(@options.file_options, self)
-      @default_dsl = DSL.new(@options.default_options, self)
-
-      if !@options[:prune_bundler]
-        default_options[:preload_app] = (@options[:workers] > 1) && Puma.forkable?
+      @events      = @_options[:events] || Events.new
+      @hooks       = {}
+      @user_dsl    = DSL.new(@_options.user_options, self)
+      @file_dsl    = DSL.new(@_options.file_options, self)
+      @default_dsl = DSL.new(@_options.default_options, self)
+
+      if !@_options[:prune_bundler]
+        default_options[:preload_app] = (@_options[:workers] > 1) && Puma.forkable?
       end
 
       @puma_bundler_pruned = env.key? 'PUMA_BUNDLER_PRUNED'
@@ -189,9 +195,18 @@ def initialize(user_options={}, default_options = {}, env = ENV, &block)
       if block
         configure(&block)
       end
+
+      @loaded = false
+      @clamped = false
     end
 
-    attr_reader :options, :plugins
+    attr_reader :plugins, :events, :hooks
+
+    def options
+      raise NotClampedError, "ensure clamp is called before accessing options" unless @clamped
+
+      @_options
+    end
 
     def configure
       yield @user_dsl, @file_dsl, @default_dsl
@@ -204,7 +219,7 @@ def configure
     def initialize_copy(other)
       @conf        = nil
       @cli_options = nil
-      @options     = @options.dup
+      @_options     = @_options.dup
     end
 
     def flatten
@@ -212,7 +227,7 @@ def flatten
     end
 
     def flatten!
-      @options = @options.flatten
+      @_options = @_options.flatten
       self
     end
 
@@ -241,18 +256,20 @@ def puma_options_from_env(env = ENV)
     end
 
     def load
+      @loaded = true
       config_files.each { |config_file| @file_dsl._load_from(config_file) }
-
-      @options
+      @_options
     end
 
     def config_files
-      files = @options.all_of(:config_files)
+      raise NotLoadedError, "ensure load is called before accessing config_files" unless @loaded
+
+      files = @_options.all_of(:config_files)
 
       return [] if files == ['-']
       return files if files.any?
 
-      first_default_file = %W(config/puma/#{@options[:environment]}.rb config/puma.rb).find do |f|
+      first_default_file = %W(config/puma/#{@_options[:environment]}.rb config/puma.rb).find do |f|
         File.exist?(f)
       end
 
@@ -260,9 +277,15 @@ def config_files
     end
 
     # Call once all configuration (included from rackup files)
-    # is loaded to flesh out any defaults
+    # is loaded to finalize defaults and lock in the configuration.
+    #
+    # This also calls load if it hasn't been called yet.
     def clamp
-      @options.finalize_values
+      load unless @loaded
+      @clamped = true
+      options.finalize_values
+      warn_hooks
+      options
     end
 
     # Injects the Configuration object into the env
@@ -281,11 +304,11 @@ def call(env)
     # Indicate if there is a properly configured app
     #
     def app_configured?
-      @options[:app] || File.exist?(rackup)
+      options[:app] || File.exist?(rackup)
     end
 
     def rackup
-      @options[:rackup]
+      options[:rackup]
     end
 
     # Load the specified rackup file, pull options from
@@ -294,9 +317,9 @@ def rackup
     def app
       found = options[:app] || load_rackup
 
-      if @options[:log_requests]
+      if options[:log_requests]
         require_relative 'commonlogger'
-        logger = @options[:custom_logger] ? options[:custom_logger] : @options[:logger]
+        logger = options[:custom_logger] ? options[:custom_logger] : options[:logger]
         found = CommonLogger.new(found, logger)
       end
 
@@ -305,7 +328,7 @@ def app
 
     # Return which environment we're running in
     def environment
-      @options[:environment]
+      options[:environment]
     end
 
     def load_plugin(name)
@@ -318,13 +341,14 @@ def load_plugin(name)
     def run_hooks(key, arg, log_writer, hook_data = nil)
       log_writer.debug "Running #{key} hooks"
 
-      @options.all_of(key).each do |b|
+      options.all_of(key).each do |hook_options|
         begin
-          if Array === b
-            hook_data[b[1]] ||= Hash.new
-            b[0].call arg, hook_data[b[1]]
+          block = hook_options[:block]
+          if id = hook_options[:id]
+            hook_data[id] ||= Hash.new
+            block.call arg, hook_data[id]
           else
-            b.call arg
+            block.call arg
           end
         rescue => e
           log_writer.log "WARNING hook #{key} failed with exception (#{e.class}) #{e.message}"
@@ -334,7 +358,7 @@ def run_hooks(key, arg, log_writer, hook_data = nil)
     end
 
     def final_options
-      @options.final_options
+      options.final_options
     end
 
     def self.temp_path
@@ -344,6 +368,12 @@ def self.temp_path
       "#{Dir.tmpdir}/puma-status-#{t}-#{$$}"
     end
 
+    def self.random_token
+      require 'securerandom' unless defined?(SecureRandom)
+
+      SecureRandom.hex(16)
+    end
+
     private
 
     def require_processor_counter
@@ -384,22 +414,34 @@ def load_rackup
       rack_app, rack_options = rack_builder.parse_file(rackup)
       rack_options = rack_options || {}
 
-      @options.file_options.merge!(rack_options)
+      options.file_options.merge!(rack_options)
 
       config_ru_binds = []
       rack_options.each do |k, v|
         config_ru_binds << v if k.to_s.start_with?("bind")
       end
 
-      @options.file_options[:binds] = config_ru_binds unless config_ru_binds.empty?
+      options.file_options[:binds] = config_ru_binds unless config_ru_binds.empty?
 
       rack_app
     end
 
-    def self.random_token
-      require 'securerandom' unless defined?(SecureRandom)
+    def warn_hooks
+      return if options[:workers] > 0
+      return if options[:silence_fork_callback_warning]
 
-      SecureRandom.hex(16)
+      @hooks.each do |key, method|
+        options.all_of(key).each do |hook_options|
+          next unless hook_options[:cluster_only]
+
+          LogWriter.stdio.log(<<~MSG.tr("\n", " "))
+            Warning: The code in the `#{method}` block will not execute
+            in the current Puma configuration. The `#{method}` block only
+            executes in Puma's cluster mode. To fix this, either remove the
+            `#{method}` call or increase Puma's worker count above zero.
+          MSG
+        end
+      end
     end
   end
 end
diff --git a/lib/puma/control_cli.rb b/lib/puma/control_cli.rb
index f2a0da3a85..bd9c64b20d 100644
--- a/lib/puma/control_cli.rb
+++ b/lib/puma/control_cli.rb
@@ -128,7 +128,8 @@ def initialize(argv, stdout=STDOUT, stderr=STDERR, env: ENV)
           require_relative 'log_writer'
 
           config = Puma::Configuration.new({ config_files: [@config_file] }, {} , env)
-          config.load
+          config.clamp
+
           @state              ||= config.options[:state]
           @control_url        ||= config.options[:control_url]
           @control_auth_token ||= config.options[:control_auth_token]
diff --git a/lib/puma/dsl.rb b/lib/puma/dsl.rb
index 9e8ef71b9c..189d3a19dd 100644
--- a/lib/puma/dsl.rb
+++ b/lib/puma/dsl.rb
@@ -13,7 +13,7 @@ module Puma
   #   config = Configuration.new({}) do |user_config|
   #     user_config.port 3001
   #   end
-  #   config.load
+  #   config.clamp
   #
   #   puts config.options[:binds] # => "tcp://127.0.0.1:3001"
   #
@@ -25,7 +25,7 @@ module Puma
   # Resulting configuration:
   #
   #   config = Configuration.new(config_file: "puma_config.rb")
-  #   config.load
+  #   config.clamp
   #
   #   puts config.options[:binds] # => "tcp://127.0.0.1:3002"
   #
@@ -733,9 +733,7 @@ def silence_fork_callback_warning
     #   end
     #
     def before_fork(&block)
-      warn_if_in_single_mode('before_fork')
-
-      process_hook :before_fork, nil, block, 'before_fork'
+      process_hook :before_fork, nil, block, 'before_fork', cluster_only: true
     end
 
     # Code to run in a worker when it boots to setup
@@ -755,9 +753,7 @@ def before_worker_boot(key = nil, &block)
         warn "on_worker_boot is deprecated, use before_worker_boot instead"
       end
 
-      warn_if_in_single_mode('before_worker_boot')
-
-      process_hook :before_worker_boot, key, block, 'before_worker_boot'
+      process_hook :before_worker_boot, key, block, 'before_worker_boot', cluster_only: true
     end
 
     alias_method :on_worker_boot, :before_worker_boot
@@ -782,9 +778,7 @@ def before_worker_shutdown(key = nil, &block)
         warn "on_worker_shutdown is deprecated, use before_worker_shutdown instead"
       end
 
-      warn_if_in_single_mode('before_worker_shutdown')
-
-      process_hook :before_worker_shutdown, key, block, 'before_worker_shutdown'
+      process_hook :before_worker_shutdown, key, block, 'before_worker_shutdown', cluster_only: true
     end
 
     alias_method :on_worker_shutdown, :before_worker_shutdown
@@ -806,9 +800,7 @@ def before_worker_fork(&block)
         warn "on_worker_fork is deprecated, use before_worker_fork instead"
       end
 
-      warn_if_in_single_mode('before_worker_fork')
-
-      process_hook :before_worker_fork, nil, block, 'before_worker_fork'
+      process_hook :before_worker_fork, nil, block, 'before_worker_fork', cluster_only: true
     end
 
     alias_method :on_worker_fork, :before_worker_fork
@@ -826,9 +818,7 @@ def before_worker_fork(&block)
     #   end
     #
     def after_worker_fork(&block)
-      warn_if_in_single_mode('after_worker_fork')
-
-      process_hook :after_worker_fork, nil, block, 'after_worker_fork'
+      process_hook :after_worker_fork, nil, block, 'after_worker_fork', cluster_only: true
     end
 
     alias_method :after_worker_boot, :after_worker_fork
@@ -845,7 +835,7 @@ def after_booted(&block)
         warn "on_booted is deprecated, use after_booted instead"
       end
 
-      @config.options[:events].after_booted(&block)
+      @config.events.after_booted(&block)
     end
 
     alias_method :on_booted, :after_booted
@@ -862,7 +852,7 @@ def after_stopped(&block)
         warn "on_stopped is deprecated, use after_stopped instead"
       end
 
-      @config.options[:events].after_stopped(&block)
+      @config.events.after_stopped(&block)
     end
     alias_method :on_stopped, :after_stopped
 
@@ -891,9 +881,7 @@ def before_refork(key = nil, &block)
         warn "on_refork is deprecated, use before_refork instead"
       end
 
-      warn_if_in_single_mode('before_refork')
-
-      process_hook :before_refork, key, block, 'before_refork'
+      process_hook :before_refork, key, block, 'before_refork', cluster_only: true
     end
 
     alias_method :on_refork, :before_refork
@@ -1472,32 +1460,21 @@ def add_pem_values_to_options_store(opts)
       end
     end
 
-    def process_hook(options_key, key, block, meth)
-      raise ArgumentError, "expected #{meth} to be given a block" unless block
+    def process_hook(options_key, key, block, method, cluster_only: false)
+      raise ArgumentError, "expected #{method} to be given a block" unless block
+
+      @config.hooks[options_key] = method
 
       @options[options_key] ||= []
-      if ON_WORKER_KEY.include? key.class
-        @options[options_key] << [block, key.to_sym]
+      hook_options = { block: block, cluster_only: cluster_only }
+      hook_options[:id] = if ON_WORKER_KEY.include? key.class
+        key.to_sym
       elsif key.nil?
-        @options[options_key] << block
+        nil
       else
-        raise "'#{meth}' key must be String or Symbol"
-      end
-    end
-
-    def warn_if_in_single_mode(hook_name)
-      return if @options[:silence_fork_callback_warning]
-      # user_options (CLI) have precedence over config file
-      workers_val = @config.options.user_options[:workers] || @options[:workers] ||
-        @config.puma_default_options[:workers] || 0
-      if workers_val == 0
-        log_string =
-          "Warning: You specified code to run in a `#{hook_name}` block, " \
-          "but Puma is not configured to run in cluster mode (worker count > 0), " \
-          "so your `#{hook_name}` block will not run."
-
-        LogWriter.stdio.log(log_string)
+        raise "'#{method}' key must be String or Symbol"
       end
+      @options[options_key] << hook_options
     end
   end
 end
diff --git a/lib/puma/launcher.rb b/lib/puma/launcher.rb
index 8ac957a5d2..f9f7152d06 100644
--- a/lib/puma/launcher.rb
+++ b/lib/puma/launcher.rb
@@ -22,12 +22,15 @@ class Launcher
     #
     # +conf+ A Puma::Configuration object indicating how to run the server.
     #
-    # +launcher_args+ A Hash that currently has one required key `:events`,
-    # this is expected to hold an object similar to an `Puma::LogWriter.stdio`,
-    # this object will be responsible for broadcasting Puma's internal state
-    # to a logging destination. An optional key `:argv` can be supplied,
-    # this should be an array of strings, these arguments are re-used when
-    # restarting the puma server.
+    # +launcher_args+ A Hash that has a few optional keys.
+    # - +:log_writer+:: Expected to hold an object similar to `Puma::LogWriter.stdio`.
+    #   This object will be responsible for broadcasting Puma's internal state
+    #   to a logging destination.
+    # - +:events+:: Expected to hold an object similar to `Puma::Events`.
+    # - +:argv+:: Expected to be an array of strings.
+    # - +:env+:: Expected to hold a hash of environment variables.
+    #
+    # These arguments are re-used when restarting the puma server.
     #
     # Examples:
     #
@@ -48,18 +51,21 @@ def initialize(conf, launcher_args={})
 
       env = launcher_args.delete(:env) || ENV
 
-      @config.options[:log_writer] = @log_writer
+      @config.clamp
+      @options = @config.options
+
+      @options[:log_writer] = @log_writer
+      @options[:logger] = @log_writer if clustered?
 
       # Advertise the Configuration
       Puma.cli_config = @config if defined?(Puma.cli_config)
+      log_config if env['PUMA_LOG_CONFIG']
 
-      @config.load
-
-      @binder        = Binder.new(@log_writer, conf)
-      @binder.create_inherited_fds(ENV).each { |k| ENV.delete k }
-      @binder.create_activated_fds(ENV).each { |k| ENV.delete k }
+      @binder        = Binder.new(@log_writer, @options)
+      @binder.create_inherited_fds(env).each { |k| env.delete k }
+      @binder.create_activated_fds(env).each { |k| env.delete k }
 
-      @environment = conf.environment
+      @environment = @config.environment
 
       # Load the systemd integration if we detect systemd's NOTIFY_SOCKET.
       # Skip this on JRuby though, because it is incompatible with the systemd
@@ -68,20 +74,17 @@ def initialize(conf, launcher_args={})
         @config.plugins.create('systemd')
       end
 
-      if @config.options[:bind_to_activated_sockets]
-        @config.options[:binds] = @binder.synthesize_binds_from_activated_fs(
-          @config.options[:binds],
-          @config.options[:bind_to_activated_sockets] == 'only'
+      if @options[:bind_to_activated_sockets]
+        @options[:binds] = @binder.synthesize_binds_from_activated_fs(
+          @options[:binds],
+          @options[:bind_to_activated_sockets] == 'only'
         )
       end
 
-      @options = @config.options
-      @config.clamp
-
       @log_writer.formatter = LogWriter::PidFormatter.new if clustered?
-      @log_writer.formatter = options[:log_formatter] if @options[:log_formatter]
+      @log_writer.formatter = @options[:log_formatter] if @options[:log_formatter]
 
-      @log_writer.custom_logger = options[:custom_logger] if @options[:custom_logger]
+      @log_writer.custom_logger = @options[:custom_logger] if @options[:custom_logger]
 
       generate_restart_data
 
@@ -97,8 +100,6 @@ def initialize(conf, launcher_args={})
       set_rack_environment
 
       if clustered?
-        @options[:logger] = @log_writer
-
         @runner = Cluster.new(self)
       else
         @runner = Single.new(self)
@@ -106,8 +107,6 @@ def initialize(conf, launcher_args={})
       Puma.stats_object = @runner
 
       @status = :run
-
-      log_config if env['PUMA_LOG_CONFIG']
     end
 
     attr_reader :binder, :log_writer, :events, :config, :options, :restart_dir
diff --git a/lib/puma/server.rb b/lib/puma/server.rb
index cb958e642a..62c628ba15 100644
--- a/lib/puma/server.rb
+++ b/lib/puma/server.rb
@@ -114,7 +114,7 @@ def initialize(app, events = nil, options = {})
       temp = !!(@options[:environment] =~ /\A(development|test)\z/)
       @leak_stack_on_error = @options[:environment] ? temp : true
 
-      @binder = Binder.new(log_writer)
+      @binder = Binder.new(log_writer, @options)
 
       ENV['RACK_ENV'] ||= "development"
 
diff --git a/lib/rack/handler/puma.rb b/lib/rack/handler/puma.rb
index 7b3ce3db83..25aaba4c87 100644
--- a/lib/rack/handler/puma.rb
+++ b/lib/rack/handler/puma.rb
@@ -32,7 +32,7 @@ def config(app, options = {})
 
       @events = options[:events] || ::Puma::Events.new
 
-      conf = ::Puma::Configuration.new(options, default_options.merge({events: @events})) do |user_config, file_config, default_config|
+      conf = ::Puma::Configuration.new(options, default_options.merge({ events: @events })) do |user_config, file_config, default_config|
         if options.delete(:Verbose)
           begin
             require 'rack/commonlogger'  # Rack 1.x
@@ -72,7 +72,7 @@ def run(app, **options)
 
       log_writer = options.delete(:Silent) ? ::Puma::LogWriter.strings : ::Puma::LogWriter.stdio
 
-      launcher = ::Puma::Launcher.new(conf, :log_writer => log_writer, events: @events)
+      launcher = ::Puma::Launcher.new(conf, log_writer: log_writer, events: @events)
 
       yield launcher if block_given?
       begin
diff --git a/test/test_binder.rb b/test/test_binder.rb
index 0ed194b76a..96dd5aad85 100644
--- a/test/test_binder.rb
+++ b/test/test_binder.rb
@@ -14,7 +14,9 @@ class TestBinderBase < PumaTest
 
   def setup
     @log_writer = Puma::LogWriter.strings
-    @binder = Puma::Binder.new(@log_writer)
+    @config = Puma::Configuration.new
+    @config.clamp
+    @binder = Puma::Binder.new(@log_writer, @config.options)
   end
 
   def teardown
@@ -424,29 +426,27 @@ def test_socket_activation_unix
   end
 
   def test_rack_multithread_default_configuration
-    binder = Puma::Binder.new(@log_writer)
-
-    assert binder.proto_env["rack.multithread"]
+    assert @binder.proto_env["rack.multithread"]
   end
 
   def test_rack_multithread_custom_configuration
     conf = Puma::Configuration.new(max_threads: 1)
+    conf.clamp
 
-    binder = Puma::Binder.new(@log_writer, conf)
+    binder = Puma::Binder.new(@log_writer, conf.options)
 
     refute binder.proto_env["rack.multithread"]
   end
 
   def test_rack_multiprocess_default_configuration
-    binder = Puma::Binder.new(@log_writer)
-
-    refute binder.proto_env["rack.multiprocess"]
+    refute @binder.proto_env["rack.multiprocess"]
   end
 
   def test_rack_multiprocess_custom_configuration
     conf = Puma::Configuration.new(workers: 1)
+    conf.clamp
 
-    binder = Puma::Binder.new(@log_writer, conf)
+    binder = Puma::Binder.new(@log_writer, conf.options)
 
     assert binder.proto_env["rack.multiprocess"]
   end
diff --git a/test/test_cli.rb b/test/test_cli.rb
index effd4fc1f6..09f6ac6395 100644
--- a/test/test_cli.rb
+++ b/test/test_cli.rb
@@ -334,8 +334,11 @@ def test_load_path
 
   def test_extra_runtime_dependencies
     cli = Puma::CLI.new ['--extra-runtime-dependencies', 'a,b']
-    extra_dependencies = cli.instance_variable_get(:@conf)
-                            .instance_variable_get(:@options)[:extra_runtime_dependencies]
+
+    conf = cli.instance_variable_get(:@conf)
+    conf.clamp
+
+    extra_dependencies = conf.options[:extra_runtime_dependencies]
 
     assert_equal %w[a b], extra_dependencies
   end
@@ -348,7 +351,10 @@ def test_environment_app_env
     cli = Puma::CLI.new []
     cli.send(:setup_options)
 
-    assert_equal 'test', cli.instance_variable_get(:@conf).environment
+    conf = cli.instance_variable_get(:@conf)
+    conf.clamp
+
+    assert_equal 'test', conf.environment
   ensure
     ENV.delete 'APP_ENV'
     ENV.delete 'RAILS_ENV'
@@ -360,7 +366,10 @@ def test_environment_rack_env
     cli = Puma::CLI.new []
     cli.send(:setup_options)
 
-    assert_equal @environment, cli.instance_variable_get(:@conf).environment
+    conf = cli.instance_variable_get(:@conf)
+    conf.clamp
+
+    assert_equal @environment, conf.environment
   end
 
   def test_environment_rails_env
@@ -370,7 +379,10 @@ def test_environment_rails_env
     cli = Puma::CLI.new []
     cli.send(:setup_options)
 
-    assert_equal @environment, cli.instance_variable_get(:@conf).environment
+    conf = cli.instance_variable_get(:@conf)
+    conf.clamp
+
+    assert_equal @environment, conf.environment
   ensure
     ENV.delete 'RAILS_ENV'
   end
diff --git a/test/test_config.rb b/test/test_config.rb
index 68a86cb8ad..8a341673b1 100644
--- a/test/test_config.rb
+++ b/test/test_config.rb
@@ -12,7 +12,9 @@ class TestConfigFile < PumaTest
   def test_default_max_threads
     max_threads = 16
     max_threads = 5 if RUBY_ENGINE.nil? || RUBY_ENGINE == 'ruby'
-    assert_equal max_threads, Puma::Configuration.new.options.default_options[:max_threads]
+    conf = Puma::Configuration.new
+    conf.clamp
+    assert_equal max_threads, conf.options.default_options[:max_threads]
   end
 
   def test_app_from_rackup
@@ -27,7 +29,7 @@ def test_app_from_rackup
     conf = Puma::Configuration.new do |c|
       c.rackup fn
     end
-    conf.load
+    conf.clamp
 
     # suppress deprecation warning of Rack (>= 2.2.0)
     # > Parsing options from the first comment line is deprecated!\n
@@ -44,7 +46,7 @@ def test_app_from_app_DSL
     conf = Puma::Configuration.new do |c|
       c.load "test/config/app.rb"
     end
-    conf.load
+    conf.clamp
 
     app = conf.app
 
@@ -57,7 +59,7 @@ def test_ssl_configuration_from_DSL
       config.load "test/config/ssl_config.rb"
     end
 
-    conf.load
+    conf.clamp
 
     bind_configuration = conf.options.file_options[:binds].first
     app = conf.app
@@ -75,7 +77,7 @@ def test_ssl_self_signed_configuration_from_DSL
       config.load "test/config/ssl_self_signed_config.rb"
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = "ssl://0.0.0.0:9292?&verify_mode=none"
     assert_equal [ssl_binding], conf.options[:binds]
@@ -93,7 +95,7 @@ def test_ssl_bind
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = "ssl://0.0.0.0:9292?cert=%2Fpath%2Fto%2Fcert&key=%2Fpath%2Fto%2Fkey&verify_mode=the_verify_mode"
     assert_equal [ssl_binding], conf.options[:binds]
@@ -112,7 +114,7 @@ def test_ssl_bind_with_escaped_filenames
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = "ssl://0.0.0.0:9292?cert=%2Fpath%2Fto%2Fcert%2B1&key=%2Fpath%2Fto%2Fkey%2B1&verify_mode=peer&ca=%2Fpath%2Fto%2Fca%2B1"
     assert_equal [ssl_binding], conf.options[:binds]
@@ -134,7 +136,7 @@ def test_ssl_bind_with_cert_and_key_pem
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = "ssl://0.0.0.0:9292?cert=store%3A0&key=store%3A1&verify_mode=the_verify_mode"
     assert_equal [ssl_binding], conf.options[:binds]
@@ -149,7 +151,7 @@ def test_ssl_bind_with_backlog
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = conf.options[:binds].first
     assert ssl_binding.include?('&backlog=2048')
@@ -165,7 +167,7 @@ def test_ssl_bind_with_low_latency_true
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = conf.options[:binds].first
     assert ssl_binding.include?('&low_latency=true')
@@ -181,7 +183,7 @@ def test_ssl_bind_with_low_latency_false
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = conf.options[:binds].first
     assert ssl_binding.include?('&low_latency=false')
@@ -203,7 +205,7 @@ def test_ssl_bind_jruby
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = "ssl://0.0.0.0:9292?keystore=/path/to/keystore" \
       "&keystore-pass=password&cipher_suites=#{ciphers}&protocols=TLSv1.2" \
@@ -226,7 +228,7 @@ def test_ssl_bind_jruby_with_ssl_cipher_list
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = "ssl://0.0.0.0:9292?keystore=/path/to/keystore" \
       "&keystore-pass=password&ssl_cipher_list=#{cipher_list}" \
@@ -249,7 +251,7 @@ def test_ssl_bind_jruby_with_truststore
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = "ssl://0.0.0.0:9292?keystore=/path/to/keystore" \
       "&keystore-pass=password&keystore-type=pkcs12" \
@@ -271,7 +273,7 @@ def test_ssl_bind_no_tlsv1_1
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = "ssl://0.0.0.0:9292?cert=%2Fpath%2Fto%2Fcert&key=%2Fpath%2Fto%2Fkey&verify_mode=the_verify_mode&no_tlsv1_1=true"
     assert_equal [ssl_binding], conf.options[:binds]
@@ -290,7 +292,7 @@ def test_ssl_bind_with_cipher_filter
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = conf.options[:binds].first
     assert ssl_binding.include?("&ssl_cipher_filter=#{cipher_filter}")
@@ -310,7 +312,7 @@ def test_ssl_bind_with_ciphersuites
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = conf.options[:binds].first
     assert ssl_binding.include?("&ssl_ciphersuites=#{ciphersuites}")
@@ -328,7 +330,7 @@ def test_ssl_bind_with_verification_flags
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = conf.options[:binds].first
     assert ssl_binding.include?("&verification_flags=TRUSTED_FIRST,NO_CHECK_TIME")
@@ -345,7 +347,7 @@ def test_ssl_bind_with_ca
       }
     end
 
-    conf.load
+    conf.clamp
 
     ssl_binding = conf.options[:binds].first
     assert_includes ssl_binding, Puma::Util.escape("/path/to/ca")
@@ -356,7 +358,7 @@ def test_lowlevel_error_handler_DSL
     conf = Puma::Configuration.new do |c|
       c.load "test/config/app.rb"
     end
-    conf.load
+    conf.clamp
 
     app = conf.options[:lowlevel_error_handler]
 
@@ -365,6 +367,7 @@ def test_lowlevel_error_handler_DSL
 
   def test_allow_users_to_override_default_options
     conf = Puma::Configuration.new(restart_cmd: 'bin/rails server')
+    conf.clamp
 
     assert_equal 'bin/rails server', conf.options[:restart_cmd]
   end
@@ -373,7 +376,7 @@ def test_overwrite_options
     conf = Puma::Configuration.new do |c|
       c.workers 3
     end
-    conf.load
+    conf.clamp
 
     assert_equal conf.options[:workers], 3
     conf.options[:workers] += 1
@@ -381,9 +384,8 @@ def test_overwrite_options
   end
 
   def test_explicit_config_files
-    conf = Puma::Configuration.new(config_files: ['test/config/settings.rb']) do |c|
-    end
-    conf.load
+    conf = Puma::Configuration.new(config_files: ['test/config/settings.rb'])
+    conf.clamp
     assert_match(/:3000$/, conf.options[:binds].first)
   end
 
@@ -391,7 +393,7 @@ def test_parameters_overwrite_files
     conf = Puma::Configuration.new(config_files: ['test/config/settings.rb']) do |c|
       c.port 3030
     end
-    conf.load
+    conf.clamp
 
     assert_match(/:3030$/, conf.options[:binds].first)
     assert_equal 3, conf.options[:min_threads]
@@ -399,37 +401,36 @@ def test_parameters_overwrite_files
   end
 
   def test_config_files_default
-    conf = Puma::Configuration.new do
-    end
+    conf = Puma::Configuration.new
+    conf.clamp
 
     assert_equal [nil], conf.config_files
   end
 
   def test_config_files_with_dash
-    conf = Puma::Configuration.new(config_files: ['-']) do
-    end
+    conf = Puma::Configuration.new(config_files: ['-'])
+    conf.clamp
 
     assert_equal [], conf.config_files
   end
 
   def test_config_files_with_existing_path
-    conf = Puma::Configuration.new(config_files: ['test/config/settings.rb']) do
-    end
+    conf = Puma::Configuration.new(config_files: ['test/config/settings.rb'])
+    conf.clamp
 
     assert_equal ['test/config/settings.rb'], conf.config_files
   end
 
   def test_config_files_with_non_existing_path
-    conf = Puma::Configuration.new(config_files: ['test/config/typo/settings.rb']) do
+    conf = Puma::Configuration.new(config_files: ['test/config/typo/settings.rb'])
+    assert_raises Errno::ENOENT do
+      conf.clamp
     end
-
-    assert_equal ['test/config/typo/settings.rb'], conf.config_files
   end
 
   def test_config_files_with_integer_convert
-    conf = Puma::Configuration.new(config_files: ['test/config/with_integer_convert.rb']) do
-    end
-    conf.load
+    conf = Puma::Configuration.new(config_files: ['test/config/with_integer_convert.rb'])
+    conf.clamp
 
     assert_equal 6, conf.options[:persistent_timeout]
     assert_equal 3, conf.options[:first_data_timeout]
@@ -444,7 +445,7 @@ def test_config_files_with_integer_convert
   def test_config_files_max_fast_inline_infinity
     conf = Puma::Configuration.new(config_files: ['test/config/max_fast_inline_infinity.rb']) do
     end
-    conf.load
+    conf.clamp
 
     assert_equal Float::INFINITY, conf.options[:max_keep_alive]
   end
@@ -452,15 +453,14 @@ def test_config_files_max_fast_inline_infinity
   def test_config_max_keep_alive_infinity
     conf = Puma::Configuration.new(config_files: ['test/config/max_keep_alive_infinity.rb']) do
     end
-    conf.load
+    conf.clamp
 
     assert_equal Float::INFINITY, conf.options[:max_keep_alive]
   end
 
   def test_config_files_with_symbol_convert
-    conf = Puma::Configuration.new(config_files: ['test/config/with_symbol_convert.rb']) do
-    end
-    conf.load
+    conf = Puma::Configuration.new(config_files: ['test/config/with_symbol_convert.rb'])
+    conf.clamp
 
     assert_equal :ruby, conf.options[:io_selector_backend]
   end
@@ -469,7 +469,7 @@ def test_config_raise_exception_on_sigterm
     conf = Puma::Configuration.new do |c|
       c.raise_exception_on_sigterm false
     end
-    conf.load
+    conf.clamp
 
     assert_equal conf.options[:raise_exception_on_sigterm], false
     conf.options[:raise_exception_on_sigterm] = true
@@ -551,7 +551,7 @@ def test_run_hooks_and_exception
         raise RuntimeError, 'Error from hook'
       end
     end
-    conf.load
+    conf.clamp
     log_writer = Puma::LogWriter.strings
 
     conf.run_hooks(:before_restart, 'ARG', log_writer)
@@ -560,11 +560,14 @@ def test_run_hooks_and_exception
   end
 
   def test_config_does_not_load_workers_by_default
-    assert_equal 0, Puma::Configuration.new.options.default_options[:workers]
+    conf = Puma::Configuration.new
+    conf.clamp
+    assert_equal 0, conf.options.default_options[:workers]
   end
 
   def test_final_options_returns_merged_options
     conf = Puma::Configuration.new({ min_threads: 1, max_threads: 2 }, { min_threads: 2 })
+    conf.clamp
 
     assert_equal 1, conf.final_options[:min_threads]
     assert_equal 2, conf.final_options[:max_threads]
@@ -572,7 +575,7 @@ def test_final_options_returns_merged_options
 
   def test_silence_single_worker_warning_default
     conf = Puma::Configuration.new
-    conf.load
+    conf.clamp
 
     assert_equal false, conf.options[:silence_single_worker_warning]
   end
@@ -581,14 +584,14 @@ def test_silence_single_worker_warning_overwrite
     conf = Puma::Configuration.new do |c|
       c.silence_single_worker_warning
     end
-    conf.load
+    conf.clamp
 
     assert_equal true, conf.options[:silence_single_worker_warning]
   end
 
   def test_silence_fork_callback_warning_default
     conf = Puma::Configuration.new
-    conf.load
+    conf.clamp
 
     assert_equal false, conf.options[:silence_fork_callback_warning]
   end
@@ -597,19 +600,57 @@ def test_silence_fork_callback_warning_overwrite
     conf = Puma::Configuration.new do |c|
       c.silence_fork_callback_warning
     end
-    conf.load
+    conf.clamp
 
     assert_equal true, conf.options[:silence_fork_callback_warning]
   end
 
   def test_http_content_length_limit
-    assert_nil Puma::Configuration.new.options.default_options[:http_content_length_limit]
+    conf = Puma::Configuration.new
+    conf.clamp
+
+    assert_nil conf.options.default_options[:http_content_length_limit]
 
     conf = Puma::Configuration.new({ http_content_length_limit: 10000})
+    conf.clamp
 
     assert_equal 10000, conf.final_options[:http_content_length_limit]
   end
 
+  def test_options_raises_not_clamped_error_when_not_clamped
+    conf = Puma::Configuration.new
+
+    error = assert_raises(Puma::Configuration::NotClampedError) do
+      conf.options
+    end
+
+    assert_equal "ensure clamp is called before accessing options", error.message
+  end
+
+  def test_options_succeeds_when_clamped
+    conf = Puma::Configuration.new
+    conf.clamp
+
+    assert_kind_of Puma::UserFileDefaultOptions, conf.options
+  end
+
+  def test_config_files_raises_not_loaded_error_when_not_loaded
+    conf = Puma::Configuration.new
+
+    error = assert_raises(Puma::Configuration::NotLoadedError) do
+      conf.config_files
+    end
+
+    assert_equal "ensure load is called before accessing config_files", error.message
+  end
+
+  def test_config_files_succeeds_when_clamped
+    conf = Puma::Configuration.new
+    conf.clamp
+
+    assert_kind_of Array, conf.config_files
+  end
+
   private
 
   def assert_run_hooks(hook_name, options = {})
@@ -619,13 +660,14 @@ def assert_run_hooks(hook_name, options = {})
     messages = []
     conf = Puma::Configuration.new do |c|
       c.silence_fork_callback_warning
+      c.send(configured_with) do |a|
+        messages << "#{hook_name} is called with #{a}"
+      end
     end
-    conf.options[hook_name] = -> (a) {
-      messages << "#{hook_name} is called with #{a}"
-    }
+    conf.clamp
 
     conf.run_hooks(hook_name, 'ARG', Puma::LogWriter.strings)
-    assert_equal messages, ["#{hook_name} is called with ARG"]
+    assert_equal ["#{hook_name} is called with ARG"], messages
 
     # test multiple
     messages = []
@@ -640,29 +682,30 @@ def assert_run_hooks(hook_name, options = {})
         messages << "#{hook_name} is called with #{a} a second time"
       end
     end
-    conf.load
+    conf.clamp
 
     conf.run_hooks(hook_name, 'ARG', Puma::LogWriter.strings)
-    assert_equal messages, ["#{hook_name} is called with ARG one time", "#{hook_name} is called with ARG a second time"]
+    assert_equal ["#{hook_name} is called with ARG one time", "#{hook_name} is called with ARG a second time"], messages
   end
 
   def assert_raise_on_hooks_without_block(hook_name)
     error = assert_raises ArgumentError do
-      Puma::Configuration.new { |c| c.send(hook_name) }.load
+      Puma::Configuration.new { |c| c.send(hook_name) }.clamp
     end
     assert_equal "expected #{hook_name} to be given a block", error.message
   end
 
   def assert_warning_for_hooks_defined_in_single_mode(hook_name)
     out, _ = capture_io do
-      Puma::Configuration.new do |c|
+      conf = Puma::Configuration.new do |c|
         c.send(hook_name) do
           # noop
         end
       end
+      conf.clamp
     end
 
-    assert_match "your `#{hook_name}` block will not run.\n", out
+    assert_match /Warning: The code in the `#{hook_name}` block will not execute in the current Puma configuration/, out
   end
 end
 
@@ -670,8 +713,8 @@ def assert_warning_for_hooks_defined_in_single_mode(hook_name)
 class TestConfigFileSingle < PumaTest
   def test_custom_logger_from_DSL
     conf = Puma::Configuration.new { |c| c.load 'test/config/custom_logger.rb' }
+    conf.clamp
 
-    conf.load
     out, _ = capture_subprocess_io { conf.options[:custom_logger].write 'test' }
 
     assert_equal "Custom logging: test\n", out
@@ -687,61 +730,74 @@ def test_double_bind_port
       user_config.bind "tcp://#{Puma::Configuration::DEFAULTS[:tcp_host]}:#{port}"
       file_config.load "test/config/app.rb"
     end
+    conf.clamp
 
-    conf.load
     assert_equal ["tcp://0.0.0.0:#{port}"], conf.options[:binds]
   end
 end
 
 class TestConfigEnvVariables < PumaTest
   def test_config_loads_correct_min_threads
-    assert_equal 0, Puma::Configuration.new.options.default_options[:min_threads]
+    conf = Puma::Configuration.new
+    conf.clamp
+    assert_equal 0, conf.options.default_options[:min_threads]
 
     env = { "MIN_THREADS" => "7" }
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal 7, conf.options.default_options[:min_threads]
 
     env = { "PUMA_MIN_THREADS" => "8" }
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal 8, conf.options.default_options[:min_threads]
 
     env = { "PUMA_MIN_THREADS" => "" }
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal 0, conf.options.default_options[:min_threads]
   end
 
   def test_config_loads_correct_max_threads
     default_max_threads = Puma.mri? ? 5 : 16
-    assert_equal default_max_threads, Puma::Configuration.new.options.default_options[:max_threads]
+    conf = Puma::Configuration.new
+    conf.clamp
+    assert_equal default_max_threads, conf.options.default_options[:max_threads]
 
     env = { "MAX_THREADS" => "7" }
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal 7, conf.options.default_options[:max_threads]
 
     env = { "PUMA_MAX_THREADS" => "8" }
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal 8, conf.options.default_options[:max_threads]
 
     env = { "PUMA_MAX_THREADS" => "" }
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal default_max_threads, conf.options.default_options[:max_threads]
   end
 
   def test_config_loads_workers_from_env
     env = { "WEB_CONCURRENCY" => "9" }
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal 9, conf.options.default_options[:workers]
   end
 
   def test_config_ignores_blank_workers_from_env
     env = { "WEB_CONCURRENCY" => "" }
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal 0, conf.options.default_options[:workers]
   end
 
   def test_config_does_not_preload_app_if_not_using_workers
     env = { "WEB_CONCURRENCY" => "0" }
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal false, conf.options.default_options[:preload_app]
   end
 
@@ -749,6 +805,7 @@ def test_config_preloads_app_if_using_workers
     env = { "WEB_CONCURRENCY" => "2" }
     preload = Puma.forkable?
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
     assert_equal preload, conf.options.default_options[:preload_app]
   end
 end
@@ -767,6 +824,7 @@ def test_config_files_with_app_env
     env = { 'APP_ENV' => 'fake-env' }
 
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
 
     assert_equal ['config/puma/fake-env.rb'], conf.config_files
   end
@@ -775,6 +833,7 @@ def test_config_files_with_rack_env
     env = { 'RACK_ENV' => 'fake-env' }
 
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
 
     assert_equal ['config/puma/fake-env.rb'], conf.config_files
   end
@@ -783,21 +842,23 @@ def test_config_files_with_rails_env
     env = { 'RAILS_ENV' => 'fake-env', 'RACK_ENV' => nil }
 
     conf = Puma::Configuration.new({}, {}, env)
+    conf.clamp
 
     assert_equal ['config/puma/fake-env.rb'], conf.config_files
   end
 
   def test_config_files_with_specified_environment
-    conf = Puma::Configuration.new
-
-    conf.options[:environment] = 'fake-env'
+    conf = Puma::Configuration.new do |c|
+      c.environment 'fake-env'
+    end
+    conf.clamp
 
     assert_equal ['config/puma/fake-env.rb'], conf.config_files
   end
 
   def test_enable_keep_alives_by_default
     conf = Puma::Configuration.new
-    conf.load
+    conf.clamp
 
     assert_equal conf.options[:enable_keep_alives], true
   end
@@ -806,7 +867,7 @@ def test_enable_keep_alives_true
     conf = Puma::Configuration.new do |c|
       c.enable_keep_alives true
     end
-    conf.load
+    conf.clamp
 
     assert_equal conf.options[:enable_keep_alives], true
   end
@@ -815,7 +876,7 @@ def test_enable_keep_alives_false
     conf = Puma::Configuration.new do |c|
       c.enable_keep_alives false
     end
-    conf.load
+    conf.clamp
 
     assert_equal conf.options[:enable_keep_alives], false
   end
diff --git a/test/test_launcher.rb b/test/test_launcher.rb
index b3ec0b88db..5720611995 100644
--- a/test/test_launcher.rb
+++ b/test/test_launcher.rb
@@ -137,7 +137,9 @@ def test_fire_after_stopped
   private
 
   def create_launcher(config = Puma::Configuration.new, lw = Puma::LogWriter.strings, **kw)
-    config.options[:binds] = ["tcp://127.0.0.1:#{UniquePort.call}"]
+    config.configure do |c|
+      c.bind "tcp://127.0.0.1:#{UniquePort.call}"
+    end
     Puma::Launcher.new(config, log_writer: lw, **kw)
   end
 end
diff --git a/test/test_rack_handler.rb b/test/test_rack_handler.rb
index 9632bc93fc..922430cc6d 100644
--- a/test/test_rack_handler.rb
+++ b/test/test_rack_handler.rb
@@ -107,7 +107,7 @@ def test_port_wins_over_config
 
           @options[:Port] = user_port
           conf = ::Rack::Handler::Puma.config(->{}, @options)
-          conf.load
+          conf.clamp
 
           assert_equal ["tcp://0.0.0.0:#{user_port}"], conf.options[:binds]
         end
@@ -128,7 +128,7 @@ def test_host_uses_supplied_port_default
       @options[:Host] = user_host
       @options[:Port] = user_port
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal ["tcp://#{user_host}:#{user_port}"], conf.options[:binds]
     end
@@ -136,7 +136,7 @@ def test_host_uses_supplied_port_default
     def test_ipv6_host_supplied_port_default
       @options[:Host] = "::1"
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal ["tcp://[::1]:9292"], conf.options[:binds]
     end
@@ -144,7 +144,7 @@ def test_ipv6_host_supplied_port_default
     def test_ssl_host_supplied_port_default
       @options[:Host] = "ssl://127.0.0.1"
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal ["ssl://127.0.0.1:9292"], conf.options[:binds]
     end
@@ -152,7 +152,7 @@ def test_ssl_host_supplied_port_default
     def test_relative_unix_host
       @options[:Host] = "./relative.sock"
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal ["unix://./relative.sock"], conf.options[:binds]
     end
@@ -160,7 +160,7 @@ def test_relative_unix_host
     def test_absolute_unix_host
       @options[:Host] = "/absolute.sock"
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal ["unix:///absolute.sock"], conf.options[:binds]
     end
@@ -168,7 +168,7 @@ def test_absolute_unix_host
     def test_abstract_unix_host
       @options[:Host] = "@abstract.sock"
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal ["unix://@abstract.sock"], conf.options[:binds]
     end
@@ -191,7 +191,7 @@ def test_config_file_wins_over_port
 
           @options[:Port] = user_port
           conf = ::Rack::Handler::Puma.config(->{}, @options)
-          conf.load
+          conf.clamp
 
           assert_equal ["tcp://0.0.0.0:#{file_port}"], conf.options[:binds]
         end
@@ -210,7 +210,7 @@ def test_default_host_when_using_config_file
           @options[:Host] = "localhost"
           @options[:Port] = user_port
           conf = ::Rack::Handler::Puma.config(->{}, @options)
-          conf.load
+          conf.clamp
 
           assert_equal ["tcp://localhost:#{file_port}"], conf.options[:binds]
         end
@@ -229,7 +229,7 @@ def test_default_host_when_using_config_file_with_explicit_host
           @options[:Host] = "localhost"
           @options[:Port] = user_port
           conf = ::Rack::Handler::Puma.config(->{}, @options)
-          conf.load
+          conf.clamp
 
           assert_equal ["tcp://1.2.3.4:#{file_port}"], conf.options[:binds]
         end
@@ -244,7 +244,7 @@ def setup
 
     def test_default_port_when_no_config_file
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal ["tcp://0.0.0.0:9292"], conf.options[:binds]
     end
@@ -258,7 +258,7 @@ def test_config_wins_over_default
           File.open("config/puma.rb", "w") { |f| f << "port #{file_port}" }
 
           conf = ::Rack::Handler::Puma.config(->{}, @options)
-          conf.load
+          conf.clamp
 
           assert_equal ["tcp://0.0.0.0:#{file_port}"], conf.options[:binds]
         end
@@ -270,7 +270,7 @@ def test_user_port_wins_over_default_when_user_supplied_is_blank
       @options[:user_supplied_options] = []
       @options[:Port] = user_port
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal ["tcp://0.0.0.0:#{user_port}"], conf.options[:binds]
     end
@@ -279,7 +279,7 @@ def test_user_port_wins_over_default
       user_port = 5001
       @options[:Port] = user_port
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal ["tcp://0.0.0.0:#{user_port}"], conf.options[:binds]
     end
@@ -295,7 +295,7 @@ def test_user_port_wins_over_config
 
           @options[:Port] = user_port
           conf = ::Rack::Handler::Puma.config(->{}, @options)
-          conf.load
+          conf.clamp
 
           assert_equal ["tcp://0.0.0.0:#{user_port}"], conf.options[:binds]
         end
@@ -304,7 +304,7 @@ def test_user_port_wins_over_config
 
     def test_default_log_request_when_no_config_file
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal false, conf.options[:log_requests]
     end
@@ -317,7 +317,7 @@ def test_file_log_requests_wins_over_default_config
       ]
 
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal file_log_requests_config, conf.options[:log_requests]
     end
@@ -331,7 +331,7 @@ def test_user_log_requests_wins_over_file_config
       ]
 
       conf = ::Rack::Handler::Puma.config(->{}, @options)
-      conf.load
+      conf.clamp
 
       assert_equal user_log_requests_config, conf.options[:log_requests]
     end
diff --git a/test/test_web_concurrency_auto.rb b/test/test_web_concurrency_auto.rb
index 84981bad1f..a32724b827 100644
--- a/test/test_web_concurrency_auto.rb
+++ b/test/test_web_concurrency_auto.rb
@@ -61,7 +61,10 @@ def test_web_concurrency_with_concurrent_ruby_unavailable
     end
 
     _, err = capture_io do
-      assert_raises(LoadError) { Puma::Configuration.new({}, {}, ENV_WC_TEST) }
+      assert_raises(LoadError) do
+        conf = Puma::Configuration.new({}, {}, ENV_WC_TEST)
+        conf.clamp
+      end
     end
     assert_includes err, 'Please add "concurrent-ruby" to your Gemfile'