diff --git a/lib/puma/configuration.rb b/lib/puma/configuration.rb
index 30992efd..da88acb6 100644
--- a/lib/puma/configuration.rb
+++ b/lib/puma/configuration.rb
@@ -137,10 +137,9 @@ module Puma
       @file_dsl    = DSL.new(@options.file_options, self)
       @default_dsl = DSL.new(@options.default_options, self)
 
-      workers_supported = !(Puma.jruby? || Puma.windows?)
 
       if !@options[:prune_bundler]
-        default_options[:preload_app] = (@options[:workers] > 1) && workers_supported
+        default_options[:preload_app] = (@options[:workers] > 1) && ::Process.respond_to?(:fork)
       end
 
       if block
@@ -174,8 +173,7 @@ module Puma
     end
 
     def default_max_threads
-      return 5 if Puma.mri?
-      16
+      Puma.mri? ? 5 : 16
     end
 
     def puma_default_options
@@ -186,7 +184,6 @@ module Puma
         :debug => false,
         :binds => ["tcp://#{DefaultTCPHost}:#{DefaultTCPPort}"],
         :workers => Integer(ENV['WEB_CONCURRENCY'] || 0),
-        :daemon => false,
         :mode => :http,
         :worker_timeout => DefaultWorkerTimeout,
         :worker_boot_timeout => DefaultWorkerTimeout,
diff --git a/test/test_config.rb b/test/test_config.rb
index 8de59b05..b78a65f7 100644
--- a/test/test_config.rb
+++ b/test/test_config.rb
@@ -6,6 +6,7 @@ require_relative "helpers/config_file"
 require "puma/configuration"
 require 'puma/events'
 
+
 class TestConfigFile < TestConfigFileBase
   parallelize_me!
 
@@ -15,51 +16,6 @@ class TestConfigFile < TestConfigFileBase
     assert_equal max_threads, Puma::Configuration.new.default_max_threads
   end
 
-  def test_config_loads_correct_min_threads
-    conf = Puma::Configuration.new
-    assert_equal 0, conf.options.default_options[:min_threads]
-
-    ENV['MIN_THREADS'] = '7'
-    conf = Puma::Configuration.new
-    assert_equal 7, conf.options.default_options[:min_threads]
-
-    ENV['PUMA_MIN_THREADS'] = '8'
-    conf = Puma::Configuration.new
-    assert_equal 8, conf.options.default_options[:min_threads]
-  end
-
-  def test_config_loads_correct_max_threads
-    conf = Puma::Configuration.new
-    assert_equal conf.default_max_threads, conf.options.default_options[:max_threads]
-
-    ENV['MAX_THREADS'] = '7'
-    conf = Puma::Configuration.new
-    assert_equal 7, conf.options.default_options[:max_threads]
-
-    ENV['PUMA_MAX_THREADS'] = '8'
-    conf = Puma::Configuration.new
-    assert_equal 8, conf.options.default_options[:max_threads]
-  end
-
-  def test_config_loads_correct_workers
-    conf = Puma::Configuration.new
-    assert_equal 0, conf.options.default_options[:workers]
-
-    ENV['WEB_CONCURRENCY'] = '8'
-    conf = Puma::Configuration.new
-    assert_equal 8, conf.options.default_options[:workers]
-  end
-
-  def test_config_preloads_app_if_using_workers
-    ENV['WEB_CONCURRENCY'] = '0'
-    conf = Puma::Configuration.new
-    assert_equal false, conf.options.default_options[:preload_app]
-
-    ENV['WEB_CONCURRENCY'] = '2'
-    preload = Puma::Plugin.new.workers_supported?
-    conf = Puma::Configuration.new
-    assert_equal preload, conf.options.default_options[:preload_app]
-  end
 
   def test_app_from_rackup
     conf = Puma::Configuration.new do |c|
@@ -327,6 +283,65 @@ class TestEnvModifificationConfig < TestConfigFileBase
   end
 end
 
+class TestConfigEnvVariables < TestConfigFileBase
+  def test_config_loads_correct_min_threads
+    conf = Puma::Configuration.new
+    assert_equal 0, conf.options.default_options[:min_threads]
+
+    with_env("MIN_THREADS" => "7") do
+      conf = Puma::Configuration.new
+      assert_equal 7, conf.options.default_options[:min_threads]
+    end
+
+    with_env("PUMA_MIN_THREADS" => "8") do
+      conf = Puma::Configuration.new
+      assert_equal 8, conf.options.default_options[:min_threads]
+    end
+  end
+
+  def test_config_loads_correct_max_threads
+    conf = Puma::Configuration.new
+    assert_equal conf.default_max_threads, conf.options.default_options[:max_threads]
+
+    with_env("MAX_THREADS" => "7") do
+      conf = Puma::Configuration.new
+      assert_equal 7, conf.options.default_options[:max_threads]
+    end
+
+    with_env("MAX_THREADS" => "8") do
+      conf = Puma::Configuration.new
+      assert_equal 8, conf.options.default_options[:max_threads]
+    end
+  end
+
+  def test_config_does_not_load_workers_by_default
+    conf = Puma::Configuration.new
+    assert_equal 0, conf.options.default_options[:workers]
+  end
+
+  def test_config_loads_workers_from_env
+    with_env("WEB_CONCURRENCY" => "9") do
+      conf = Puma::Configuration.new
+      assert_equal 9, conf.options.default_options[:workers]
+    end
+  end
+
+  def test_config_does_not_preload_app_if_using_workers
+    with_env("WEB_CONCURRENCY" => "0") do
+      conf = Puma::Configuration.new
+      assert_equal false, conf.options.default_options[:preload_app]
+    end
+  end
+
+  def test_config_preloads_app_if_using_workers
+    with_env("WEB_CONCURRENCY" => "2") do
+      preload = Puma::Plugin.new.workers_supported?
+      conf = Puma::Configuration.new
+      assert_equal preload, conf.options.default_options[:preload_app]
+    end
+  end
+end
+
 class TestConfigFileWithFakeEnv < TestConfigFileBase
   def setup
     FileUtils.mkpath("config/puma")