diff --git a/README.md b/README.md
index 4743f20..baaed2e 100644
--- a/README.md
+++ b/README.md
@@ -93,13 +93,13 @@ end
 
 # :manufacturer and :year should be Car's instance methods(like ActiveRecord columns)
 class Car < ActiveRecord::Base
-    protokoll :code, :scoped_by => lambda { |o| "#{o.manufacturer}-#{o.year}" }
+    protokoll :code, :scope_by => lambda { |o| "#{o.manufacturer}-#{o.year}" }
 end
 # will scope Cars by for example "Ford-2016"
 
 # :manufacturer and :year should be Car's instance methods(like ActiveRecord columns)
 class Car < ActiveRecord::Base
-    protokoll :code, :scoped_by => Proc.new{ "#{manufacturer}-#{model}" }
+    protokoll :code, :scope_by => Proc.new{ "#{manufacturer}-#{model}" }
 end
 # will scope Cars by for example "Ford-Mustang", "Chevrolet-Camaro"
 ```
@@ -140,6 +140,10 @@ Run the generator
 
     rails g protokoll:migration
 
+Optional: If scope_by will be used run next generator as well
+
+    rails g protokoll:migration:scope_by
+
 and migrate your database
 
     rake db:migrate
diff --git a/lib/generators/protokoll/migration/scope_by_generator.rb b/lib/generators/protokoll/migration/scope_by_generator.rb
new file mode 100644
index 0000000..679d4e3
--- /dev/null
+++ b/lib/generators/protokoll/migration/scope_by_generator.rb
@@ -0,0 +1,26 @@
+require 'rails/generators'
+
+module Protokoll
+  module Generators
+    module Migration
+      class ScopeByGenerator < ::Rails::Generators::Base
+
+        include Rails::Generators::Migration
+
+        desc "Generate protokoll's scope_by migration"
+        def create_migration_file
+          migration_name = "add_scope_by_to_custom_auto_increments.rb"
+          migration_template migration_name, File.join('db', 'migrate', migration_name)
+        end
+
+        def self.source_root
+          @source_root ||= File.expand_path(File.join(File.dirname(__FILE__), 'templates'))
+        end
+
+        def self.next_migration_number(path)
+          Time.now.utc.strftime("%Y%m%d%H%M%S")
+        end
+      end
+    end
+  end
+end
diff --git a/lib/generators/protokoll/migration/templates/add_scope_by_to_custom_auto_increments.rb b/lib/generators/protokoll/migration/templates/add_scope_by_to_custom_auto_increments.rb
new file mode 100644
index 0000000..d927195
--- /dev/null
+++ b/lib/generators/protokoll/migration/templates/add_scope_by_to_custom_auto_increments.rb
@@ -0,0 +1,12 @@
+class AddScopeByToCustomAutoIncrements < ActiveRecord::Migration
+  def up
+    add_column :custom_auto_increments, :counter_model_scope, :string
+    add_index :custom_auto_increments, [:counter_model_name, :counter_model_scope],
+              :unique => true, :name => :counter_model_name_scope
+  end
+
+  def down
+    remove_index :custom_auto_increments, name: :counter_model_name_scope
+    remove_column :custom_auto_increments, :counter_model_scope, :string
+  end
+end
diff --git a/lib/generators/protokoll/migration/templates/create_custom_auto_increments.rb b/lib/generators/protokoll/migration/templates/create_custom_auto_increments.rb
index 4525e81..93fba87 100644
--- a/lib/generators/protokoll/migration/templates/create_custom_auto_increments.rb
+++ b/lib/generators/protokoll/migration/templates/create_custom_auto_increments.rb
@@ -2,13 +2,11 @@ class CreateCustomAutoIncrements < ActiveRecord::Migration
   def up
     create_table :custom_auto_increments, :force => true do |t|
       t.string  :counter_model_name
-      t.string  :counter_model_scope
       t.integer :counter, :default => 0
       t.timestamps
     end
 
     add_index :custom_auto_increments, :counter_model_name
-    add_index :custom_auto_increments, [:counter_model_name, :counter_model_scope], :unique => true
   end
 
   def down
diff --git a/test/dummy/db/migrate/20120222164124_create_custom_auto_increments.rb b/test/dummy/db/migrate/20120222164124_create_custom_auto_increments.rb
index bf318bb..b559411 100644
--- a/test/dummy/db/migrate/20120222164124_create_custom_auto_increments.rb
+++ b/test/dummy/db/migrate/20120222164124_create_custom_auto_increments.rb
@@ -2,13 +2,11 @@ class CreateCustomAutoIncrements < ActiveRecord::Migration
   def up
     create_table :custom_auto_increments, :force => true do |t|
       t.string :counter_model_name
-      t.string :counter_model_scope
       t.integer :counter, :default => 0
       t.timestamps
     end
 
     add_index :custom_auto_increments, :counter_model_name
-    add_index :custom_auto_increments, [:counter_model_name, :counter_model_scope], :unique => true, name: 'counter_model_name_by_scope'
   end
 
   def down
diff --git a/test/dummy/db/migrate/20160310030821_add_scope_by_to_custom_auto_increments.rb b/test/dummy/db/migrate/20160310030821_add_scope_by_to_custom_auto_increments.rb
new file mode 100644
index 0000000..d927195
--- /dev/null
+++ b/test/dummy/db/migrate/20160310030821_add_scope_by_to_custom_auto_increments.rb
@@ -0,0 +1,12 @@
+class AddScopeByToCustomAutoIncrements < ActiveRecord::Migration
+  def up
+    add_column :custom_auto_increments, :counter_model_scope, :string
+    add_index :custom_auto_increments, [:counter_model_name, :counter_model_scope],
+              :unique => true, :name => :counter_model_name_scope
+  end
+
+  def down
+    remove_index :custom_auto_increments, name: :counter_model_name_scope
+    remove_column :custom_auto_increments, :counter_model_scope, :string
+  end
+end
diff --git a/test/dummy/db/schema.rb b/test/dummy/db/schema.rb
index 9f50e2e..c40daaa 100644
--- a/test/dummy/db/schema.rb
+++ b/test/dummy/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20120222164124) do
+ActiveRecord::Schema.define(version: 20160310030821) do
 
   create_table "calls", force: :cascade do |t|
     t.string   "number"
@@ -21,13 +21,13 @@
 
   create_table "custom_auto_increments", force: :cascade do |t|
     t.string   "counter_model_name"
-    t.string   "counter_model_scope"
     t.integer  "counter",             default: 0
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.string   "counter_model_scope"
   end
 
-  add_index "custom_auto_increments", ["counter_model_name", "counter_model_scope"], name: "counter_model_name_by_scope", unique: true
+  add_index "custom_auto_increments", ["counter_model_name", "counter_model_scope"], name: "counter_model_name_scope", unique: true
   add_index "custom_auto_increments", ["counter_model_name"], name: "index_custom_auto_increments_on_counter_model_name"
 
   create_table "protocols", force: :cascade do |t|