diff --git a/.github/workflows/rspec.yml b/.github/workflows/rspec.yml
index 50c587b..c481f6d 100644
--- a/.github/workflows/rspec.yml
+++ b/.github/workflows/rspec.yml
@@ -13,8 +13,9 @@ jobs:
         ruby-version:
           - "3.3"
           - "3.4"
+          - "4.0"
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: ruby/setup-ruby@v1
         with:
           bundler-cache: true
diff --git a/README.md b/README.md
index 0278349..454efad 100644
--- a/README.md
+++ b/README.md
@@ -47,3 +47,9 @@ development:
   port: <%= ENV.fetch('REDIS_PORT') { Config.port(:redis, 6379) } %>
   url: <%= ENV.fetch('REDIS_URL') { Config.port(:redis, 6379, 'redis://localhost:%s/') } %>
 ```
+
+Reset the cached map of ports with:
+
+```ruby
+Compose.reset!
+```
diff --git a/lib/compose.rb b/lib/compose.rb
index 7ae58ce..a89cf87 100644
--- a/lib/compose.rb
+++ b/lib/compose.rb
@@ -36,4 +36,8 @@ def self.enabled?
     ENV['RAILS_DISABLE_COMPOSE'].to_s.empty? &&
       Kernel.system('docker', '--version', out: File::NULL, err: File::NULL)
   end
+
+  def self.reset!
+    @ports = nil
+  end
 end
diff --git a/spec/compose_spec.rb b/spec/compose_spec.rb
index d529796..1072307 100644
--- a/spec/compose_spec.rb
+++ b/spec/compose_spec.rb
@@ -24,7 +24,6 @@
           .and_return false
       end
 
-
       it 'returns false' do
         expect(described_class.enabled?).to be false
       end