diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 4ca52a1..5722d72 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -9,10 +9,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v1
-    - name: Set up Ruby 2.6
-      uses: actions/setup-ruby@v1
+    - name: Set up Ruby 2.6.7
+      uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 2.6.x
+        ruby-version: 2.6.7
     - name: Build and test with Rake
       run: |
         gem install bundler
diff --git a/Gemfile b/Gemfile
index eacacf1..8b13e71 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,5 +4,5 @@ source 'https://rubygems.org'
 gemspec
 
 gem 'dotenv', '~> 2.1', '>= 2.1.1'
-gem 'webmock', '~> 2.1'
+gem 'webmock', '~> 3.5'
 gem 'vcr', '~> 3.0', '>= 3.0.3'
diff --git a/lib/convertkit/client.rb b/lib/convertkit/client.rb
index 8132d2b..d80e67e 100644
--- a/lib/convertkit/client.rb
+++ b/lib/convertkit/client.rb
@@ -17,15 +17,16 @@ class Client
     include Webhooks
     include Tags
 
-    attr_accessor :api_secret, :api_key
+    attr_accessor :api_secret, :api_key, :integration_key
 
-    def initialize( api_key=nil, api_secret=nil )
+    def initialize( api_key=nil, api_secret=nil, integration_key=nil )
       @api_secret = api_secret || Convertkit.configuration.api_secret
       @api_key = api_key || Convertkit.configuration.api_key
+      @integration_key = integration_key || Convertkit.configuration.integration_key
     end
 
     def connection
-      @connection ||= Connection.new(api_key: api_key, api_secret: api_secret)
+      @connection ||= Connection.new(api_key: api_key, api_secret: api_secret, integration_key: integration_key)
     end
   end
 end
diff --git a/lib/convertkit/configuration.rb b/lib/convertkit/configuration.rb
index 07fe421..536d5df 100644
--- a/lib/convertkit/configuration.rb
+++ b/lib/convertkit/configuration.rb
@@ -1,6 +1,6 @@
 module Convertkit
   class Configuration
-    attr_accessor :api_secret, :api_key
+    attr_accessor :api_secret, :api_key, :integration_key
     attr_accessor :timeout, :open_timeout
 
     def initialize
diff --git a/lib/convertkit/connection.rb b/lib/convertkit/connection.rb
index a3fa832..cdf211e 100644
--- a/lib/convertkit/connection.rb
+++ b/lib/convertkit/connection.rb
@@ -7,8 +7,8 @@ module Convertkit
   class Connection
     attr_reader :http_connection
 
-    def initialize(api_key: nil, api_secret: nil)
-      @http_connection = faraday_connection(api_key, api_secret)
+    def initialize(api_key: nil, api_secret: nil, integration_key: nil)
+      @http_connection = faraday_connection(api_key, api_secret, integration_key)
     end
 
     def content_type
@@ -33,7 +33,7 @@ def delete(*args, &blk)
 
     private
 
-    def faraday_connection(api_key, api_secret)
+    def faraday_connection(api_key, api_secret, integration_key)
       Faraday.new do |f|
         f.url_prefix = "https://api.convertkit.com/v3/"
         f.adapter :net_http
@@ -47,6 +47,7 @@ def faraday_connection(api_key, api_secret)
 
         f.params['api_secret'] = api_secret if api_secret
         f.params['api_key'] = api_key if api_key
+        f.params['integration_key'] = integration_key if integration_key
 
         f.response :json, content_type: /\bjson$/
       end
diff --git a/spec/convertkit/convertkit_spec.rb b/spec/convertkit/convertkit_spec.rb
index 875c767..4dd05b3 100644
--- a/spec/convertkit/convertkit_spec.rb
+++ b/spec/convertkit/convertkit_spec.rb
@@ -30,6 +30,14 @@
       expect(Convertkit.configuration.api_key).to eql("new_key")
     end
 
+    it "sets the integration_key value" do
+      Convertkit.configure do |config|
+        config.integration_key = "new_key"
+      end
+
+      expect(Convertkit.configuration.integration_key).to eql("new_key")
+    end
+
     it "sets the timeout value" do
       Convertkit.configure do |config|
         config.timeout = 10