diff --git a/Rakefile b/Rakefile
index 270ab5cfc5..63aab4ffd5 100644
--- a/Rakefile
+++ b/Rakefile
@@ -35,7 +35,7 @@ end
 
 Rake::TestTask.new(:test) do |t|
   t.libs << "test"
-  t.libs << "lib"
+  t.verbose = true
   t.test_files = FileList['test/**/test_*.rb']
 end
 
diff --git a/lib/rdoc.rb b/lib/rdoc.rb
index d7bed75167..e50c3bcdba 100644
--- a/lib/rdoc.rb
+++ b/lib/rdoc.rb
@@ -125,8 +125,6 @@ def self.load_yaml
 
   autoload :RDoc,           'rdoc/rdoc'
 
-  autoload :TestCase,       'rdoc/test_case'
-
   autoload :CrossReference, 'rdoc/cross_reference'
   autoload :ERBIO,          'rdoc/erbio'
   autoload :ERBPartial,     'rdoc/erb_partial'
diff --git a/rdoc.gemspec b/rdoc.gemspec
index fdd65e6e2b..bb3af71671 100644
--- a/rdoc.gemspec
+++ b/rdoc.gemspec
@@ -63,5 +63,5 @@ RDoc includes the +rdoc+ and +ri+ tools for generating and displaying documentat
   s.add_development_dependency("rake")
   s.add_development_dependency("racc", "> 1.4.10")
   s.add_development_dependency("kpeg")
-  s.add_development_dependency("minitest", "~> 4")
+  s.add_development_dependency("minitest", "~> 5")
 end
diff --git a/test/minitest_helper.rb b/test/minitest_helper.rb
index 5f38870324..1814669bf9 100644
--- a/test/minitest_helper.rb
+++ b/test/minitest_helper.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 begin
-  gem 'minitest', '~> 4.0' unless defined?(Test::Unit)
+  gem 'minitest', '~> 5.0'
 rescue NoMethodError, Gem::LoadError
   # for ruby tests
 end
@@ -29,7 +29,7 @@
 # * <code>@pwd</code> containing the current working directory
 # * FileUtils, pp, Tempfile, Dir.tmpdir and StringIO
 
-class RDoc::TestCase < MiniTest::Unit::TestCase
+class RDoc::TestCase < (defined?(Minitest::Test) ? Minitest::Test : MiniTest::Unit::TestCase)
 
   ##
   # Abstract test-case setup
diff --git a/test/xref_test_case.rb b/test/xref_test_case.rb
index 9a87166ad2..70b7df4222 100644
--- a/test/xref_test_case.rb
+++ b/test/xref_test_case.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 ENV['RDOC_TEST'] = 'yes'
 
-require 'rdoc'
+require 'minitest_helper'
 require File.expand_path '../xref_data', __FILE__
 
 class XrefTestCase < RDoc::TestCase