diff --git a/Rakefile b/Rakefile
index 7d03146..93b3e16 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,6 +1,6 @@
 #!/usr/bin/env rake
-require 'bundler/gem_tasks'
-require 'rspec/core/rake_task'
+require "bundler/gem_tasks"
+require "rspec/core/rake_task"
 
 RSpec::Core::RakeTask.new(:spec)
 
diff --git a/lib/slugtastic.rb b/lib/slugtastic.rb
index e108ebf..6e36a79 100644
--- a/lib/slugtastic.rb
+++ b/lib/slugtastic.rb
@@ -1,12 +1,12 @@
-require 'slugtastic/version'
-require 'slugtastic/model_additions'
-require 'slugtastic/railtie' if defined? Rails
+require "slugtastic/version"
+require "slugtastic/model_additions"
+require "slugtastic/railtie" if defined? Rails
 
 module Slugtastic
   def self.generate_slug(string, delimiter = nil)
     return if string.nil?
     slug = string.parameterize
-    slug.gsub!('-', delimiter) if delimiter
+    slug.gsub!("-", delimiter) if delimiter
     slug
   end
 end
diff --git a/lib/slugtastic/model_additions.rb b/lib/slugtastic/model_additions.rb
index e7bf34d..d8be2cd 100644
--- a/lib/slugtastic/model_additions.rb
+++ b/lib/slugtastic/model_additions.rb
@@ -2,8 +2,8 @@ module Slugtastic
   module ModelAdditions
     # To generate a slug from another value, call <tt>has_slug</tt> in any
     # ActiveRecord model and pass in the name of the slug attribute.
-    # By default the slug will be generated from the <tt>title</tt> attribute, but
-    # you can specify by adding <tt>:from => {attribute}</tt>.
+    # By default the slug will be generated from the <tt>title</tt> attribute,
+    # but you can specify by adding <tt>:from => {attribute}</tt>.
     #
     #   class Article < ActiveRecord::Base
     #     has_slug :slug, :from => :title
@@ -11,17 +11,15 @@ module Slugtastic
     #
     def slug(name, options = {})
       options.reverse_merge!(from: :title)
+
       before_validation do
         if send(name).nil? || send(name).blank?
-          send("#{name}=", Slugtastic.generate_slug(send(options[:from]), options[:delimiter]))
+          send(
+            "#{name}=",
+            Slugtastic.generate_slug(send(options[:from]), options[:delimiter]),
+          )
         end
       end
     end
-
-    def has_slug(name, options = {})
-      $stderr.puts '[deprecated] Slugtastic: `has_slug` has been renamed `slug` and will likely '\
-                   'be removed in a future version.'
-      slug(name, options)
-    end
   end
 end
diff --git a/lib/slugtastic/railtie.rb b/lib/slugtastic/railtie.rb
index 97c1b22..f597cc0 100644
--- a/lib/slugtastic/railtie.rb
+++ b/lib/slugtastic/railtie.rb
@@ -1,6 +1,6 @@
 module Slugtastic
   class Railtie < Rails::Railtie
-    initializer 'slugtastic.model_additions' do
+    initializer "slugtastic.model_additions" do
       ActiveSupport.on_load :active_record do
         extend ModelAdditions
       end
diff --git a/lib/slugtastic/version.rb b/lib/slugtastic/version.rb
index 669f9ff..e77c7c3 100644
--- a/lib/slugtastic/version.rb
+++ b/lib/slugtastic/version.rb
@@ -1,3 +1,3 @@
 module Slugtastic
-  VERSION = '1.3.0'.freeze
+  VERSION = "1.3.0".freeze
 end
diff --git a/slugtastic.gemspec b/slugtastic.gemspec
index b7ea25f..ce9d9b9 100644
--- a/slugtastic.gemspec
+++ b/slugtastic.gemspec
@@ -1,22 +1,24 @@
 # -*- encoding: utf-8 -*-
-require File.expand_path('../lib/slugtastic/version', __FILE__)
+
+require File.expand_path("lib/slugtastic/version", __dir__)
 
 Gem::Specification.new do |gem|
   gem.authors       = ["Dan Barber"]
   gem.email         = ["danbee@gmail.com"]
-  gem.licenses      = ['MIT']
-  gem.description   = %q{A simple slug string generator for ActiveRecord. Will populate a slug attribute from another attribute.}
-  gem.summary       = %q{A simple slug string generator for ActiveRecord.}
+  gem.licenses      = ["MIT"]
+  gem.description   = "A simple slug string generator for ActiveRecord. " \
+                      "Will populate a slug attribute from another attribute."
+  gem.summary       = "A simple slug string generator for ActiveRecord."
   gem.homepage      = "http://danbarber.me/slugtastic"
 
   gem.files         = `git ls-files`.split($\)
-  gem.executables   = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
+  gem.executables   = gem.files.grep(%r{^bin/}).map { |f| File.basename(f) }
   gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
   gem.name          = "slugtastic"
   gem.require_paths = ["lib"]
   gem.version       = Slugtastic::VERSION
 
-  gem.add_development_dependency "rake", "~> 11.1"
-  gem.add_development_dependency "rspec", "~> 3.4"
-  gem.add_development_dependency "supermodel", "~> 0"
+  gem.add_development_dependency "activemodel", "~> 5"
+  gem.add_development_dependency "rake", "~> 12.3"
+  gem.add_development_dependency "rspec", "~> 3.7"
 end
diff --git a/spec/slugtastic/model_additions_spec.rb b/spec/slugtastic/model_additions_spec.rb
index 5c66243..968130a 100644
--- a/spec/slugtastic/model_additions_spec.rb
+++ b/spec/slugtastic/model_additions_spec.rb
@@ -1,9 +1,27 @@
 # encoding: utf-8
-require 'spec_helper'
 
-class BaseModel < SuperModel::Base
+require "spec_helper"
+require "active_support/core_ext/hash/reverse_merge"
+require "active_model"
+
+class BaseModel
   include ActiveModel::Validations::Callbacks
   extend Slugtastic::ModelAdditions
+
+  def initialize(attrs = {})
+    attrs.each do |key, value|
+      instance_variable_set(:"@#{key}", value)
+    end
+  end
+
+  def self.create!(attrs)
+    new(attrs).save
+  end
+
+  def save
+    _run_validation_callbacks
+    self
+  end
 end
 
 class Model < BaseModel
@@ -18,37 +36,30 @@ end
 
 class ModelDelimiter < BaseModel
   attr_accessor :slug, :title
-  slug :slug, delimiter: '_'
-end
-
-class ModelAlias < BaseModel
-  attr_accessor :slug, :title
-  has_slug :slug
+  slug :slug, delimiter: "_"
 end
 
 describe Slugtastic::ModelAdditions do
-  it 'generates a slug from the name' do
-    expect(Model.create!(name: 'A Simple Name').slug).to eq 'a-simple-name'
+  it "generates a slug from the name" do
+    expect(Model.create!(name: "A Simple Name").slug).to eq "a-simple-name"
   end
 
-  it 'defaults to generating the slug from title' do
-    expect(ModelDefault.create!(title: 'A Simple Title').slug).to eq 'a-simple-title'
+  it "defaults to generating the slug from title" do
+    expect(ModelDefault.create!(title: "A Simple Title").slug)
+      .to eq "a-simple-title"
   end
 
-  it 'generates a slug from the title with delimiter substitutions' do
-    expect(ModelDelimiter.create!(title: 'A Simple Title').slug).to eq 'a_simple_title'
+  it "generates a slug from the title with delimiter substitutions" do
+    expect(ModelDelimiter.create!(title: "A Simple Title").slug)
+      .to eq "a_simple_title"
   end
 
   it "doesn't regenerate the slug if it already exists" do
-    model = Model.create!(name: 'A Simple Name')
-    expect(model.slug).to eq 'a-simple-name'
+    model = Model.create!(name: "A Simple Name")
+    expect(model.slug).to eq "a-simple-name"
 
-    model.title = 'A new title'
+    model.name = "A new title"
     model.save
-    expect(model.slug).to eq 'a-simple-name'
-  end
-
-  it 'aliases slug to has_slug for backwards compatibility' do
-    expect(ModelAlias.create!(title: 'A Simple Title').slug).to eq 'a-simple-title'
+    expect(model.slug).to eq "a-simple-name"
   end
 end
diff --git a/spec/slugtastic_spec.rb b/spec/slugtastic_spec.rb
index f2a3e53..13b75aa 100644
--- a/spec/slugtastic_spec.rb
+++ b/spec/slugtastic_spec.rb
@@ -1,35 +1,43 @@
 # encoding: utf-8
-require 'spec_helper'
+
+require "spec_helper"
 
 describe Slugtastic do
-  describe '.generate_slug' do
-    it 'returns empty if the input string is empty' do
-      expect(Slugtastic.generate_slug('')).to eq ''
+  describe ".generate_slug" do
+    it "returns empty if the input string is empty" do
+      expect(Slugtastic.generate_slug("")).to eq ""
     end
 
-    it 'generates a slug from a simple string' do
-      expect(Slugtastic.generate_slug('A simple string.')).to eq 'a-simple-string'
+    it "generates a slug from a simple string" do
+      expect(Slugtastic.generate_slug("A simple string."))
+        .to eq "a-simple-string"
     end
 
-    it 'substitutes hyphens for delimiter if specified' do
-      expect(Slugtastic.generate_slug('A simple string.', '_')).to eq 'a_simple_string'
+    it "substitutes hyphens for delimiter if specified" do
+      expect(Slugtastic.generate_slug("A simple string.", "_"))
+        .to eq "a_simple_string"
     end
 
-    it 'generates a slug from a string with numbers' do
-      expect(Slugtastic.generate_slug('Slugtastic was built in 2012.')).to eq 'slugtastic-was-built-in-2012'
+    it "generates a slug from a string with numbers" do
+      expect(Slugtastic.generate_slug("Slugtastic was built in 2012."))
+        .to eq "slugtastic-was-built-in-2012"
     end
 
-    it 'handles strings with hypens in them' do
-      expect(Slugtastic.generate_slug('A string - with Hyphens')).to eq 'a-string-with-hyphens'
+    it "handles strings with hypens in them" do
+      expect(Slugtastic.generate_slug("A string - with Hyphens"))
+        .to eq "a-string-with-hyphens"
     end
 
-    it 'handles strings with other characters in them' do
-      expect(Slugtastic.generate_slug('A string, with /All sorts!')).to eq 'a-string-with-all-sorts'
+    it "handles strings with other characters in them" do
+      expect(Slugtastic.generate_slug("A string, with /All sorts!"))
+        .to eq "a-string-with-all-sorts"
     end
 
-    it 'handles basic transliteration' do
-      expect(Slugtastic.generate_slug('Un été À la maison.')).to eq 'un-ete-a-la-maison'
-      expect(Slugtastic.generate_slug('Ātri brūna lapsa')).to eq 'atri-bruna-lapsa'
+    it "handles basic transliteration" do
+      expect(Slugtastic.generate_slug("Un été À la maison."))
+        .to eq "un-ete-a-la-maison"
+      expect(Slugtastic.generate_slug("Ātri brūna lapsa"))
+        .to eq "atri-bruna-lapsa"
     end
   end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 25053aa..34a0a94 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,2 +1 @@
-require 'slugtastic'
-require 'supermodel'
+require "slugtastic"