diff --git a/CHANGELOG.md b/CHANGELOG.md
index 14f45af..f1e29e4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,22 @@
 # CHANGELOG
 
+## Version 0.3.1
+
+### Improvements
+
+- Adds `build_slug/2` to accept the original `changeset` as the second argument, it still receives list of `sources` as the first argument
+- Updates `build_slug/1` inner logic
+
+### Documentation
+
+- Updates `README.md` with the new example
+- Updates docs to handle new changes
+- Updates `CONTRIBUTING.md` with 'Development' section
+
+### Testing
+
+- Adds new test cases to cover `build_slug/2`
+
 
 ## Version 0.3.0
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index bae8354..00fedc0 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,11 +1,19 @@
 # Contributing to EctoAutoslugField
 
 ## Pull Requests Welcome
-1. Fork ecto_autoslug_field
+1. Fork `ecto_autoslug_field`
 2. Create a topic branch
 3. Make logically-grouped commits with clear commit messages
 4. Push commits to your fork
-5. Open a pull request against ecto_autoslug_field/master
+5. Open a pull request against `ecto_autoslug_field/master`
+
+## Development
+
+Please, make sure that all these commands succeed before pushing anything:
+
+1. `mix test`
+2. `mix credo --strict`
+3. `mix dialyzer` (it may take long on the first run)
 
 ## Issues
 
diff --git a/README.md b/README.md
index 34d5ca9..d8c8ade 100644
--- a/README.md
+++ b/README.md
@@ -49,79 +49,39 @@ Optional:
 The simplest example:
 
 ```elixir
-defmodule NameSlug do
-  use EctoAutoslugField.Slug, from: :name, to: :slug
+defmodule EctoSlugs.Blog.Article.TitleSlug do
+  use EctoAutoslugField.Slug, from: :title, to: :slug
 end
 
-defmodule User do
+defmodule EctoSlugs.Blog.Article do
   use Ecto.Schema
   import Ecto.Changeset
+  alias EctoSlugs.Blog.Article
+  alias EctoSlugs.Blog.Article.TitleSlug
 
-  schema "users" do
-    field :name, :string
-    field :slug, NameSlug.Type
-  end
-
-  @required_fields ~w(name)
-  @optional_fields ~w(slug)
-
-  def changeset(model, params \\ :empty) do
-    model
-    |> cast(params, @required_fields, @optional_fields)
-    |> NameSlug.maybe_generate_slug
-    |> NameSlug.unique_constraint
-  end
-end
-```
-
-More complex example:
-
-```elixir
-defmodule ComplexSlug do
-  use EctoAutoslugField.Slug, to: :slug
-
-  def get_sourses(changeset, _opts) do
-    # This function is used to get sources to build slug from:
-    base_fields = [:title]
-
-    if get_change(changeset, :breaking, false) do
-      base_fields ++ ["breaking"]
-    else
-      base_fields
-    end
-  end
+  schema "blog_articles" do
+    field :breaking, :boolean, default: false
+    field :content, :string
+    field :title, :string
 
-  def build_slug(sources, _changeset) do
-    # Custom slug building rule:
-    sources
-    |> Enum.join("-")
-    |> Slugger.slugify_downcase
-    |> String.replace("-", "+")
-  end
-end
+    field :slug, TitleSlug.Type
 
-defmodule Article do
-  use Ecto.Schema
-  import Ecto.Changeset
-
-  schema "articles" do
-    field :title, :string
-    field :breaking, :boolean
-    field :slug, ComplexSlug.Type
+    timestamps()
   end
 
-  @required_fields ~w(title breaking)
-  @optional_fields ~w(slug)
-
-  def changeset(model, params \\ :empty) do
-    model
-    |> cast(params, @required_fields, @optional_fields)
-    |> ComplexSlug.maybe_generate_slug
-    |> ComplexSlug.unique_constraint
+  def changeset(%Article{} = article, attrs) do
+    article
+    |> cast(attrs, [:title, :content, :breaking])
+    |> validate_required([:title, :content])
+    |> unique_constraint(:title)
+    |> TitleSlug.maybe_generate_slug
+    |> TitleSlug.unique_constraint
   end
 end
 ```
 
+More complex examples are cover in [this tutorial](https://medium.com/wemake-services/creating-slugs-for-ecto-schemas-7349513410f0).
+
 ## Changelog
 
 See [CHANGELOG.md](https://github.com/sobolevn/ecto_autoslug_field/blob/master/CHANGELOG.md).
diff --git a/mix.exs b/mix.exs
index 91dcf7e..4bf9bd0 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,7 +1,7 @@
 defmodule EctoAutoslugField.Mixfile do
   use Mix.Project
 
-  @version "0.3.0"
+  @version "0.3.1"
   @url "https://github.com/sobolevn/ecto_autoslug_field"
 
   def project do