diff --git a/.ruby-version b/.ruby-version
index aedc15b..37c2961 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-2.5.3
+2.7.2
diff --git a/Gemfile.lock b/Gemfile.lock
index 5e7a6f4..a66b0e2 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,48 +2,50 @@ PATH
   remote: .
   specs:
     castle-middleware (1.0.0)
-      castle-rb (< 5.0)
+      castle-rb (< 7.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    byebug (10.0.2)
-    castle-rb (4.2.0)
-    coveralls_reborn (0.12.0)
-      json (~> 2.1)
-      simplecov (~> 0.16.1)
+    byebug (11.1.3)
+    castle-rb (5.0.0)
+    coveralls_reborn (0.20.0)
+      simplecov (>= 0.18.1, < 0.22.0)
       term-ansicolor (~> 1.6)
-      thor (~> 0.20.0)
+      thor (>= 0.20.3, < 2.0)
       tins (~> 1.16)
-    diff-lcs (1.3)
-    docile (1.3.1)
-    json (2.1.0)
-    rake (12.3.2)
-    rspec (3.8.0)
-      rspec-core (~> 3.8.0)
-      rspec-expectations (~> 3.8.0)
-      rspec-mocks (~> 3.8.0)
-    rspec-core (3.8.0)
-      rspec-support (~> 3.8.0)
-    rspec-expectations (3.8.2)
+    diff-lcs (1.4.4)
+    docile (1.3.5)
+    rake (13.0.3)
+    rspec (3.10.0)
+      rspec-core (~> 3.10.0)
+      rspec-expectations (~> 3.10.0)
+      rspec-mocks (~> 3.10.0)
+    rspec-core (3.10.1)
+      rspec-support (~> 3.10.0)
+    rspec-expectations (3.10.1)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.8.0)
-    rspec-mocks (3.8.0)
+      rspec-support (~> 3.10.0)
+    rspec-mocks (3.10.1)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.8.0)
-    rspec-support (3.8.0)
-    simplecov (0.16.1)
+      rspec-support (~> 3.10.0)
+    rspec-support (3.10.1)
+    simplecov (0.21.2)
       docile (~> 1.1)
-      json (>= 1.8, < 3)
-      simplecov-html (~> 0.10.0)
-    simplecov-html (0.10.2)
-    term-ansicolor (1.7.0)
+      simplecov-html (~> 0.11)
+      simplecov_json_formatter (~> 0.1)
+    simplecov-html (0.12.3)
+    simplecov_json_formatter (0.1.2)
+    sync (0.5.0)
+    term-ansicolor (1.7.1)
       tins (~> 1.0)
-    thor (0.20.3)
-    tins (1.20.2)
+    thor (1.0.1)
+    tins (1.28.0)
+      sync
 
 PLATFORMS
   ruby
+  x86_64-darwin-19
 
 DEPENDENCIES
   byebug
@@ -53,4 +55,4 @@ DEPENDENCIES
   rspec
 
 BUNDLED WITH
-   1.17.3
+   2.2.1
diff --git a/castle-middleware.gemspec b/castle-middleware.gemspec
index 71a7d6b..b370719 100644
--- a/castle-middleware.gemspec
+++ b/castle-middleware.gemspec
@@ -21,5 +21,5 @@ Gem::Specification.new do |spec|
   spec.require_paths = ['lib']
 
   spec.required_ruby_version = '>= 2.3.0'
-  spec.add_dependency 'castle-rb', '< 5.0'
+  spec.add_dependency 'castle-rb', '< 7.0'
 end
diff --git a/spec/castle/middleware_spec.rb b/spec/castle/middleware_spec.rb
index 3f43527..fc09ba8 100644
--- a/spec/castle/middleware_spec.rb
+++ b/spec/castle/middleware_spec.rb
@@ -6,7 +6,7 @@
 
     it { expect(config.api_secret).to be_eql('secret') }
 
-    it { expect(Castle.config.port).to be_eql(3000) }
+    it { expect(Castle.config.url.to_s).to be_eql('https://api.castle.local:3000') }
   end
 
   describe '::configure' do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 9611cac..d0dcb46 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -12,7 +12,7 @@
   config.before do
     ::Castle::Middleware.configure do |c|
       c.api_secret = 'secret'
-      c.api_options = { port: 3000 }
+      c.api_options = { url: 'https://api.castle.local:3000' }
       c.app_id = '1234'
       c.file_path = './spec/castle/middleware/castle_config.yml'
     end