diff --git a/Rakefile b/Rakefile
index 84f3a2b..ad73624 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,10 +1,12 @@
-require "rake/testtask"
-require "rake/extensiontask"
+# frozen_string_literal: true
+
+require 'rake/testtask'
+require 'rake/extensiontask'
 
 Rake::TestTask.new do |t|
   t.verbose = true
 end
 
-Rake::ExtensionTask.new "cruzzy" do |ext|
-  ext.lib_dir = "lib/cruzzy"
+Rake::ExtensionTask.new 'cruzzy' do |ext|
+  ext.lib_dir = 'lib/cruzzy'
 end
diff --git a/bin/dummy.rb b/bin/dummy.rb
index 4b227fb..9487c7d 100644
--- a/bin/dummy.rb
+++ b/bin/dummy.rb
@@ -1,5 +1,7 @@
-require "ruzzy"
+# frozen_string_literal: true
 
-dummy_test_one_input = lambda {|data| Ruzzy.c_dummy_test_one_input(data)}
+require 'ruzzy'
+
+dummy_test_one_input = ->(data) { Ruzzy.c_dummy_test_one_input(data) }
 
 Ruzzy.fuzz(dummy_test_one_input)
diff --git a/ext/cruzzy/extconf.rb b/ext/cruzzy/extconf.rb
index 024e2d3..82cac56 100644
--- a/ext/cruzzy/extconf.rb
+++ b/ext/cruzzy/extconf.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'mkmf'
 
 create_makefile('cruzzy/cruzzy')
diff --git a/lib/ruzzy.rb b/lib/ruzzy.rb
index d5ae95c..2d4cf17 100644
--- a/lib/ruzzy.rb
+++ b/lib/ruzzy.rb
@@ -1,11 +1,13 @@
+# frozen_string_literal: true
+
+# A Ruby C extension fuzzer
 module Ruzzy
-  require "cruzzy/cruzzy"
+  require 'cruzzy/cruzzy'
 
-  # $0 is the program name
-  DEFAULT_ARGS = [$0] + ARGV
+  DEFAULT_ARGS = [$PROGRAM_NAME] + ARGV
 
   def fuzz(test_one_input, args = DEFAULT_ARGS)
-    self.c_fuzz(test_one_input, args)
+    c_fuzz(test_one_input, args)
   end
 
   module_function :fuzz
diff --git a/ruzzy.gemspec b/ruzzy.gemspec
index 4c2233a..14c322b 100644
--- a/ruzzy.gemspec
+++ b/ruzzy.gemspec
@@ -1,16 +1,19 @@
-require "rake"
+# frozen_string_literal: true
+
+require 'rake'
 
 Gem::Specification.new do |s|
-  s.name        = "ruzzy"
-  s.version     = "0.5.0"
-  s.summary     = "A Ruby C extension fuzzer"
-  s.authors     = ["Trail of Bits"]
-  s.email       = "support@trailofbits.com"
-  s.files       = FileList["lib/**/*.rb", "ext/**/*.{rb,c,h}"]
-  s.homepage    = "https://rubygems.org/gems/ruzzy"
-  s.license     = "AGPL-3.0"
-  s.extensions  = %w[ext/cruzzy/extconf.rb]
+  s.name                  = 'ruzzy'
+  s.version               = '0.5.0'
+  s.summary               = 'A Ruby C extension fuzzer'
+  s.authors               = ['Trail of Bits']
+  s.email                 = 'support@trailofbits.com'
+  s.files                 = FileList['lib/**/*.rb', 'ext/**/*.{rb,c,h}']
+  s.homepage              = 'https://rubygems.org/gems/ruzzy'
+  s.license               = 'AGPL-3.0'
+  s.extensions            = %w[ext/cruzzy/extconf.rb]
+  s.required_ruby_version = '>= 3.1.0'
 
-  s.add_development_dependency "rake", '~> 13.0'
-  s.add_development_dependency "rake-compiler", '~> 1.2'
+  s.add_development_dependency 'rake', '~> 13.0'
+  s.add_development_dependency 'rake-compiler', '~> 1.2'
 end
diff --git a/test/test_ruzzy.rb b/test/test_ruzzy.rb
index 4ad57a6..de54a49 100644
--- a/test/test_ruzzy.rb
+++ b/test/test_ruzzy.rb
@@ -1,26 +1,28 @@
-require "ruzzy"
-require "test/unit"
+# frozen_string_literal: true
+
+require 'ruzzy'
+require 'test/unit'
 
 class RuzzyTest < Test::Unit::TestCase
   def test_c_libfuzzer_is_loaded
-    result = Ruzzy.c_libfuzzer_is_loaded()
+    result = Ruzzy.c_libfuzzer_is_loaded
 
     assert_true(result)
   end
 
   def test_c_dummy_test_one_input_proc
-    dummy_test_one_input = proc {|data| Ruzzy.c_dummy_test_one_input(data)}
+    dummy_test_one_input = proc { |data| Ruzzy.c_dummy_test_one_input(data) }
 
-    result = dummy_test_one_input.call("test")
+    result = dummy_test_one_input.call('test')
     expected = 0
 
     assert_equal(result, expected)
   end
 
   def test_c_dummy_test_one_input_lambda
-    dummy_test_one_input = lambda {|data| Ruzzy.c_dummy_test_one_input(data)}
+    dummy_test_one_input = ->(data) { Ruzzy.c_dummy_test_one_input(data) }
 
-    result = dummy_test_one_input.call("test")
+    result = dummy_test_one_input.call('test')
     expected = 0
 
     assert_equal(result, expected)
@@ -28,7 +30,7 @@ def test_c_dummy_test_one_input_lambda
 
   def test_fuzz_without_proc
     assert_raise(RuntimeError) do
-      Ruzzy.fuzz("not a proc")
+      Ruzzy.fuzz('not a proc')
     end
   end
 end