diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000..a95dad9
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,7 @@
+source 'https://rubygems.org'
+
+gemspec
+# For test OCR
+gem 'rtesseract'
+gem 'mini_magick'
+gem 'active_support'
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 0000000..64132bb
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,44 @@
+PATH
+  remote: .
+  specs:
+    rucaptcha (0.1.3)
+      posix-spawn (>= 0.3.0)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    diff-lcs (1.2.5)
+    mini_magick (4.3.6)
+    mini_portile (0.6.2)
+    nokogiri (1.6.6.2)
+      mini_portile (~> 0.6.0)
+    posix-spawn (0.3.11)
+    rake (10.4.2)
+    rspec (3.3.0)
+      rspec-core (~> 3.3.0)
+      rspec-expectations (~> 3.3.0)
+      rspec-mocks (~> 3.3.0)
+    rspec-core (3.3.2)
+      rspec-support (~> 3.3.0)
+    rspec-expectations (3.3.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.3.0)
+    rspec-mocks (3.3.2)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.3.0)
+    rspec-support (3.3.0)
+    rtesseract (1.3.1)
+      nokogiri
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  mini_magick
+  rake
+  rspec (>= 3.3.0)
+  rtesseract
+  rucaptcha!
+
+BUNDLED WITH
+   1.10.6
diff --git a/lib/rucaptcha.rb b/lib/rucaptcha.rb
index b65ce13..a75661a 100644
--- a/lib/rucaptcha.rb
+++ b/lib/rucaptcha.rb
@@ -1,4 +1,6 @@
-require 'active_support/core_ext'
+require 'rails'
+require 'action_controller'
+require 'active_support/all'
 require_relative 'rucaptcha/version'
 require_relative 'rucaptcha/configuration'
 require_relative 'rucaptcha/controller_helpers'
diff --git a/lib/rucaptcha/controller_helpers.rb b/lib/rucaptcha/controller_helpers.rb
index 4314833..e46cd8d 100644
--- a/lib/rucaptcha/controller_helpers.rb
+++ b/lib/rucaptcha/controller_helpers.rb
@@ -13,7 +13,7 @@ module RuCaptcha
 
     def random_rucaptcha_chars
       chars = SecureRandom.hex(RuCaptcha.config.len / 2).downcase
-      chars.gsub!(/[0ol1]/i, (rand(9) + 1).to_s)
+      chars.gsub!(/[0ol1]/i, (rand(8) + 2).to_s)
       chars
     end
 
diff --git a/spec/configure_spec.rb b/spec/configure_spec.rb
new file mode 100644
index 0000000..3063bea
--- /dev/null
+++ b/spec/configure_spec.rb
@@ -0,0 +1,12 @@
+require 'spec_helper'
+
+describe RuCaptcha do
+  describe 'normal' do
+    it 'should read right config with spec_helper set' do
+      expect(RuCaptcha.config.len).to eq(2)
+      expect(RuCaptcha.config.width).to eq(123)
+      expect(RuCaptcha.config.height).to eq(33)
+      expect(RuCaptcha.config.implode).to eq(0.111)
+    end
+  end
+end
diff --git a/spec/controller_helpers_spec.rb b/spec/controller_helpers_spec.rb
new file mode 100644
index 0000000..1a3ecc1
--- /dev/null
+++ b/spec/controller_helpers_spec.rb
@@ -0,0 +1,59 @@
+require 'spec_helper'
+
+describe RuCaptcha do
+  class Simple < ActionController::Base
+    def session
+      @session ||= {}
+    end
+
+    def params
+      @params ||= {}
+    end
+  end
+
+  let(:simple) { Simple.new }
+
+  describe '.generate_rucaptcha' do
+    it 'should work' do
+      expect(simple).to receive(:random_rucaptcha_chars).and_return('abcd')
+      expect(simple.generate_rucaptcha).not_to be_nil
+      expect(simple.session[:_rucaptcha]).to eq('abcd')
+    end
+  end
+
+  describe '.random_rucaptcha_chars' do
+    it 'should len equal config.len' do
+      expect(simple.random_rucaptcha_chars.length).to eq(RuCaptcha.config.len)
+    end
+
+    it 'should return 0-9 and lower str' do
+      expect(simple.random_rucaptcha_chars).to match(/[a-z0-9]/)
+    end
+
+    it 'should not include [0ol1]' do
+      10000.times do
+        expect(simple.random_rucaptcha_chars).not_to match(/[0ol1]/i)
+      end
+    end
+  end
+
+  describe '.verify_rucaptcha?' do
+    context 'Correct chars in params' do
+      it 'should work' do
+        simple.session[:_rucaptcha] = 'abcd'
+        simple.params[:_rucaptcha] = 'Abcd'
+        expect(simple.verify_rucaptcha?).to eq(true)
+        simple.params[:_rucaptcha] = 'AbcD'
+        expect(simple.verify_rucaptcha?).to eq(true)
+      end
+    end
+
+    describe 'Incorrect chars' do
+      it "should work" do
+        simple.session[:_rucaptcha] = 'abcd'
+        simple.params[:_rucaptcha] = 'd123'
+        expect(simple.verify_rucaptcha?).to eq(false)
+      end
+    end
+  end
+end
diff --git a/spec/ocr_spec.rb b/spec/ocr_spec.rb
new file mode 100644
index 0000000..69a556f
--- /dev/null
+++ b/spec/ocr_spec.rb
@@ -0,0 +1,34 @@
+require 'spec_helper'
+
+describe 'OCR' do
+  before do
+    @samples = []
+    10.times do
+      @samples << SecureRandom.hex(2)
+    end
+    @filenames = []
+    @samples.each do |chars|
+      fname = File.join(File.dirname(__FILE__), "..", "tmp", "#{chars}.png")
+      img = RuCaptcha::Captcha.create(chars)
+      File.open(fname, 'w+') do |f|
+        f.puts img
+      end
+      @filenames << fname
+    end
+  end
+
+  after do
+    `rm #{File.join(File.dirname(__FILE__), '../tmp/*.png')}`
+  end
+
+  it 'should not read by OCR lib' do
+    results = []
+    @samples.each do |chars|
+      str = RTesseract.new(File.join(File.dirname(__FILE__), "..", "tmp", "#{chars}.png")).to_s
+      results << "- Chars: #{chars}, OCR read #{str.strip}"
+      expect(chars).not_to eq(str)
+    end
+
+    puts %(------------------------\nOCR all results: \n#{results.join("\n")})
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
new file mode 100644
index 0000000..80d706c
--- /dev/null
+++ b/spec/spec_helper.rb
@@ -0,0 +1,14 @@
+require 'rubygems'
+
+$LOAD_PATH.unshift(File.dirname(__FILE__))
+$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
+
+require 'rucaptcha'
+require 'rtesseract'
+
+RuCaptcha.configure do
+  self.len = 2
+  self.width = 123
+  self.height = 33
+  self.implode = 0.111
+end