diff --git a/lib/faraday/connection.rb b/lib/faraday/connection.rb
index 6318de585..a6c3f1f95 100644
--- a/lib/faraday/connection.rb
+++ b/lib/faraday/connection.rb
@@ -577,7 +577,7 @@ def proxy_from_env(url)
         case url
         when String
           uri = Utils.URI(url)
-          uri = URI.parse("#{uri.scheme}://#{uri.hostname}").find_proxy
+          uri = URI.parse("#{uri.scheme}://#{uri.host}").find_proxy
         when URI
           uri = url.find_proxy
         when nil
diff --git a/spec/faraday/connection_spec.rb b/spec/faraday/connection_spec.rb
index 5c7e3b60c..50112f9c9 100644
--- a/spec/faraday/connection_spec.rb
+++ b/spec/faraday/connection_spec.rb
@@ -18,6 +18,13 @@
     it { expect(subject.path_prefix).to eq('/fish') }
     it { expect(subject.params).to eq('a' => '1') }
   end
+
+  context 'with IPv6 address' do
+    let(:address) { 'http://[::1]:85/' }
+
+    it { expect(subject.host).to eq('[::1]') }
+    it { expect(subject.port).to eq(85) }
+  end
 end
 
 shared_examples 'default connection options' do