diff --git a/Rakefile b/Rakefile
index 809eb56..19cb6b8 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,2 +1,9 @@
 require "bundler/gem_tasks"
+require 'rake/testtask'
 
+Rake::TestTask.new do |t|
+  t.libs << "test"
+  t.test_files = Dir['test/**/*_test.rb']
+end
+
+task :default => :test
diff --git a/test/test_helper.rb b/test/test_helper.rb
new file mode 100644
index 0000000..990195e
--- /dev/null
+++ b/test/test_helper.rb
@@ -0,0 +1,2 @@
+require 'minitest/autorun'
+require 'twik'
diff --git a/test/twik/python_test.rb b/test/twik/python_test.rb
new file mode 100644
index 0000000..428961e
--- /dev/null
+++ b/test/twik/python_test.rb
@@ -0,0 +1,52 @@
+require 'test_helper'
+
+# Port of the tests from Twik Python version
+class Twik::PythonTest < Minitest::Test
+  PRIVATE_KEY = 'TFCY2AJI-NBPU-V01E-F7CP-PJIZNRKPF25W'
+  MASTER_KEY = 'foobar'
+  TAG = 'tag'
+
+  VALUES = {
+    alphanumeric_and_special_chars: {
+      4 => 'm3/I',
+      8 => 'mb/5AsJ9',
+      12 => 'mb/5AsJ9Uon7',
+      22 => 'mb15As*9Uon7ZzvcsXMjpV',
+      26 => 'mb15AsJ9&on7ZzvcsXMjpVLTqQ',
+    },
+    alphanumeric: {
+      4 => 'm31I',
+      8 => 'mb15AsJ9',
+      12 => 'mb15AsJ9Uon7',
+      22 => 'mb15AsJ9Uon7ZzvcsXMjpV',
+      26 => 'mb15AsJ9Uon7ZzvcsXMjpVLTqQ',
+    },
+    numeric: {
+      4 => '4315',
+      8 => '43154099',
+      12 => '431540992657',
+      22 => '4315409926570734032171',
+      26 => '43154099265707340321711986',
+    }
+  }
+
+  def setup
+    @twik = Twik.new(PRIVATE_KEY)
+  end
+
+  VALUES.keys.each do |type|
+    define_method(:"test_password_#{type}") do
+      @twik.type = type
+
+      VALUES[type].each do |length,value|
+        assert_equal value, @twik.generate(TAG, MASTER_KEY, length: length)
+      end
+    end
+  end
+
+  def test_size
+    (1..26).each do |length|
+      assert_equal length, @twik.generate(TAG, MASTER_KEY, length: length).length
+    end
+  end
+end
diff --git a/test/twik_test.rb b/test/twik_test.rb
new file mode 100644
index 0000000..3d09ba2
--- /dev/null
+++ b/test/twik_test.rb
@@ -0,0 +1,33 @@
+require 'test_helper'
+
+class TwikTest < Minitest::Test
+  def setup
+    @twik = Twik.new('TEST')
+  end
+
+  def test_that_generates_password
+    @twik.length = 16
+
+    assert_equal 'N4eCufjtnKRM+8dK', @twik.generate('test', 'test', type: :alphanumeric_and_special_chars)
+    assert_equal 'N4eCufjtnKRMK8dK', @twik.generate('test', 'test', type: :alphanumeric)
+    assert_equal '4483382261839821', @twik.generate('test', 'test', type: :numeric)
+  end
+
+  def test_that_length_is_correct
+    assert_equal 1, @twik.generate('test', 'test', length: 1).length
+    assert_equal 26, @twik.generate('test', 'test', length: 26).length
+    assert_equal 8, @twik.generate('test', 'test', length: 8).length
+  end
+
+  def test_that_type_is_numeric
+    assert_match(/\A[0-9]+\z/, @twik.generate('test', 'test', type: :numeric))
+  end
+
+  def test_that_type_is_alphanumeric
+    assert_match(/\A[A-Za-z0-9]+\z/, @twik.generate('test', 'test', type: :alphanumeric))
+  end
+
+  def test_that_type_is_alphanumeric_and_special_chars
+    refute_match(/\A[A-Za-z0-9]+\z/, @twik.generate('test', 'test', type: :alphanumeric_and_special_chars))
+  end
+end
diff --git a/twik.gemspec b/twik.gemspec
index f9c088a..5c9567e 100644
--- a/twik.gemspec
+++ b/twik.gemspec
@@ -20,4 +20,6 @@ Gem::Specification.new do |spec|
 
   spec.add_development_dependency "bundler", "~> 1.7"
   spec.add_development_dependency "rake", "~> 10.0"
+
+  spec.add_development_dependency 'minitest', '~> 5.4'
 end