diff --git a/demos/embedded/src/test/java/org/eclipse/jetty/demos/ProxyServerTest.java b/demos/embedded/src/test/java/org/eclipse/jetty/demos/ProxyServerTest.java
index 1ea27c25a8e..4598ab768b6 100644
--- a/demos/embedded/src/test/java/org/eclipse/jetty/demos/ProxyServerTest.java
+++ b/demos/embedded/src/test/java/org/eclipse/jetty/demos/ProxyServerTest.java
@@ -40,7 +40,7 @@ public class ProxyServerTest extends AbstractEmbeddedTest
         server.start();
 
         URI uri = server.getURI();
-        client.getProxyConfiguration().getProxies().add(new HttpProxy("localhost", uri.getPort()));
+        client.getProxyConfiguration().addProxy(new HttpProxy("localhost", uri.getPort()));
     }
 
     @AfterEach
diff --git a/documentation/jetty-documentation/src/main/java/org/eclipse/jetty/docs/programming/client/http/HTTPClientDocs.java b/documentation/jetty-documentation/src/main/java/org/eclipse/jetty/docs/programming/client/http/HTTPClientDocs.java
index 91ddace1291..4b71a9b6978 100644
--- a/documentation/jetty-documentation/src/main/java/org/eclipse/jetty/docs/programming/client/http/HTTPClientDocs.java
+++ b/documentation/jetty-documentation/src/main/java/org/eclipse/jetty/docs/programming/client/http/HTTPClientDocs.java
@@ -659,7 +659,7 @@ public class HTTPClientDocs
 
         // Add the new proxy to the list of proxies already registered.
         ProxyConfiguration proxyConfig = httpClient.getProxyConfiguration();
-        proxyConfig.getProxies().add(proxy);
+        proxyConfig.addProxy(proxy);
 
         ContentResponse response = httpClient.GET("http://domain.com/path");
         // end::proxy[]
@@ -684,7 +684,7 @@ public class HTTPClientDocs
         // Proxy configuration.
         ProxyConfiguration proxyConfig = httpClient.getProxyConfiguration();
         HttpProxy proxy = new HttpProxy("proxy.net", 8080);
-        proxyConfig.getProxies().add(proxy);
+        proxyConfig.addProxy(proxy);
 
         ContentResponse response = httpClient.newRequest(serverURI).send();
         // end::proxyAuthentication[]
diff --git a/documentation/jetty-documentation/src/main/java/org/eclipse/jetty/docs/programming/client/websocket/WebSocketClientDocs.java b/documentation/jetty-documentation/src/main/java/org/eclipse/jetty/docs/programming/client/websocket/WebSocketClientDocs.java
index dce2373692b..85835c4461f 100644
--- a/documentation/jetty-documentation/src/main/java/org/eclipse/jetty/docs/programming/client/websocket/WebSocketClientDocs.java
+++ b/documentation/jetty-documentation/src/main/java/org/eclipse/jetty/docs/programming/client/websocket/WebSocketClientDocs.java
@@ -54,7 +54,7 @@ public class WebSocketClientDocs
         // Instantiate and configure HttpClient.
         HttpClient httpClient = new HttpClient();
         // For example, configure a proxy.
-        httpClient.getProxyConfiguration().getProxies().add(new HttpProxy("localhost", 8888));
+        httpClient.getProxyConfiguration().addProxy(new HttpProxy("localhost", 8888));
 
         // Instantiate WebSocketClient, passing HttpClient to the constructor.
         WebSocketClient webSocketClient = new WebSocketClient(httpClient);
diff --git a/jetty-client/src/main/java/org/eclipse/jetty/client/ProxyConfiguration.java b/jetty-client/src/main/java/org/eclipse/jetty/client/ProxyConfiguration.java
index c826ced88f2..e3922c4fd43 100644
--- a/jetty-client/src/main/java/org/eclipse/jetty/client/ProxyConfiguration.java
+++ b/jetty-client/src/main/java/org/eclipse/jetty/client/ProxyConfiguration.java
@@ -14,13 +14,14 @@
 package org.eclipse.jetty.client;
 
 import java.net.URI;
-import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Objects;
 import java.util.Set;
 
 import org.eclipse.jetty.http.HttpScheme;
 import org.eclipse.jetty.io.ClientConnectionFactory;
+import org.eclipse.jetty.util.BlockingArrayQueue;
 import org.eclipse.jetty.util.HostPort;
 import org.eclipse.jetty.util.ssl.SslContextFactory;
 
@@ -30,23 +31,50 @@ import org.eclipse.jetty.util.ssl.SslContextFactory;
  * Applications add subclasses of {@link Proxy} to this configuration via:
  * <pre>
  * ProxyConfiguration proxyConfig = httpClient.getProxyConfiguration();
- * proxyConfig.getProxies().add(new HttpProxy(proxyHost, 8080));
+ * proxyConfig.addProxy(new HttpProxy(proxyHost, 8080));
  * </pre>
  *
  * @see HttpClient#getProxyConfiguration()
  */
 public class ProxyConfiguration
 {
-    private final List<Proxy> proxies = new ArrayList<>();
+    private final List<Proxy> proxies = new BlockingArrayQueue<>();
 
+    /**
+     * @deprecated use {@link #addProxy(Proxy)} and {@link #removeProxy(Proxy)} instead
+     * @return the forward proxies to use
+     */
+    @Deprecated(forRemoval = true)
     public List<Proxy> getProxies()
     {
         return proxies;
     }
 
+    /**
+     * Adds a proxy.
+     *
+     * @param proxy a proxy
+     * @throws NullPointerException if {@code proxy} is null
+     */
+    public void addProxy(Proxy proxy)
+    {
+        proxies.add(Objects.requireNonNull(proxy));
+    }
+
+    /**
+     * Removes a proxy.
+     *
+     * @param proxy a proxy
+     * @return true if a match is found
+     */
+    public boolean removeProxy(Proxy proxy)
+    {
+        return proxies.remove(proxy);
+    }
+
     public Proxy match(Origin origin)
     {
-        for (Proxy proxy : getProxies())
+        for (Proxy proxy : proxies)
         {
             if (proxy.matches(origin))
                 return proxy;
diff --git a/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientCustomProxyTest.java b/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientCustomProxyTest.java
index 6cb964dcd83..6e0e36a99af 100644
--- a/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientCustomProxyTest.java
+++ b/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientCustomProxyTest.java
@@ -98,7 +98,7 @@ public class HttpClientCustomProxyTest
         // Setup the custom proxy
         int proxyPort = connector.getLocalPort();
         int serverPort = proxyPort + 1; // Any port will do for these tests - just not the same as the proxy
-        client.getProxyConfiguration().getProxies().add(new CAFEBABEProxy(new Origin.Address("localhost", proxyPort), false));
+        client.getProxyConfiguration().addProxy(new CAFEBABEProxy(new Origin.Address("localhost", proxyPort), false));
 
         ContentResponse response = client.newRequest(serverHost, serverPort)
             .timeout(5, TimeUnit.SECONDS)
diff --git a/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientProxyProtocolTest.java b/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientProxyProtocolTest.java
index 9c882e73948..1ecf680d806 100644
--- a/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientProxyProtocolTest.java
+++ b/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientProxyProtocolTest.java
@@ -231,7 +231,7 @@ public class HttpClientProxyProtocolTest
 
         int proxyPort = connector.getLocalPort();
         int serverPort = proxyPort + 1; // Any port will do.
-        client.getProxyConfiguration().getProxies().add(new HttpProxy("localhost", proxyPort));
+        client.getProxyConfiguration().addProxy(new HttpProxy("localhost", proxyPort));
 
         // We are simulating to be a HttpClient inside a proxy.
         // The server is configured with the PROXY protocol to know the socket address of clients.
diff --git a/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientProxyTest.java b/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientProxyTest.java
index 3c158d6888c..c7b00eeba15 100644
--- a/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientProxyTest.java
+++ b/jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientProxyTest.java
@@ -60,7 +60,7 @@ public class HttpClientProxyTest extends AbstractHttpClientServerTest
 
         int proxyPort = connector.getLocalPort();
         int serverPort = proxyPort + 1; // Any port will do for these tests - just not the same as the proxy
-        client.getProxyConfiguration().getProxies().add(new HttpProxy("localhost", proxyPort));
+        client.getProxyConfiguration().addProxy(new HttpProxy("localhost", proxyPort));
 
         ContentResponse response = client.newRequest(serverHost, serverPort)
             .scheme(scenario.getScheme())
@@ -108,7 +108,7 @@ public class HttpClientProxyTest extends AbstractHttpClientServerTest
         String proxyHost = "localhost";
         int proxyPort = connector.getLocalPort();
         int serverPort = proxyPort + 1; // Any port will do for these tests - just not the same as the proxy
-        client.getProxyConfiguration().getProxies().add(new HttpProxy(proxyHost, proxyPort));
+        client.getProxyConfiguration().addProxy(new HttpProxy(proxyHost, proxyPort));
 
         ContentResponse response1 = client.newRequest(serverHost, serverPort)
             .scheme(scenario.getScheme())
@@ -202,7 +202,7 @@ public class HttpClientProxyTest extends AbstractHttpClientServerTest
         });
 
         int proxyPort = connector.getLocalPort();
-        client.getProxyConfiguration().getProxies().add(new HttpProxy(proxyHost, proxyPort));
+        client.getProxyConfiguration().addProxy(new HttpProxy(proxyHost, proxyPort));
 
         ContentResponse response1 = client.newRequest(serverHost, serverPort)
             .scheme(scenario.getScheme())
@@ -290,7 +290,7 @@ public class HttpClientProxyTest extends AbstractHttpClientServerTest
         client.getAuthenticationStore().addAuthentication(new BasicAuthentication(proxyURI, proxyRealm, "proxyUser", "proxyPassword"));
         URI serverURI = URI.create(scenario.getScheme() + "://" + serverHost + ":" + serverPort);
         client.getAuthenticationStore().addAuthentication(new BasicAuthentication(serverURI, serverRealm, "serverUser", "serverPassword"));
-        client.getProxyConfiguration().getProxies().add(new HttpProxy(proxyHost, proxyPort));
+        client.getProxyConfiguration().addProxy(new HttpProxy(proxyHost, proxyPort));
         final AtomicInteger requests = new AtomicInteger();
         client.getRequestListeners().add(new Request.Listener.Adapter()
         {
@@ -361,7 +361,7 @@ public class HttpClientProxyTest extends AbstractHttpClientServerTest
         int serverPort = proxyPort + 1;
         URI proxyURI = URI.create(scenario.getScheme() + "://" + proxyHost + ":" + proxyPort);
         client.getAuthenticationStore().addAuthentication(new BasicAuthentication(proxyURI, proxyRealm, "proxyUser", "proxyPassword"));
-        client.getProxyConfiguration().getProxies().add(new HttpProxy(proxyHost, proxyPort));
+        client.getProxyConfiguration().addProxy(new HttpProxy(proxyHost, proxyPort));
         final AtomicInteger requests = new AtomicInteger();
         client.getRequestListeners().add(new Request.Listener.Adapter()
         {
diff --git a/jetty-client/src/test/java/org/eclipse/jetty/client/Socks4ProxyTest.java b/jetty-client/src/test/java/org/eclipse/jetty/client/Socks4ProxyTest.java
index 97770100b26..898836eb115 100644
--- a/jetty-client/src/test/java/org/eclipse/jetty/client/Socks4ProxyTest.java
+++ b/jetty-client/src/test/java/org/eclipse/jetty/client/Socks4ProxyTest.java
@@ -77,7 +77,7 @@ public class Socks4ProxyTest
     public void testSocks4Proxy() throws Exception
     {
         int proxyPort = proxy.socket().getLocalPort();
-        client.getProxyConfiguration().getProxies().add(new Socks4Proxy("localhost", proxyPort));
+        client.getProxyConfiguration().addProxy(new Socks4Proxy("localhost", proxyPort));
 
         CountDownLatch latch = new CountDownLatch(1);
 
@@ -139,7 +139,7 @@ public class Socks4ProxyTest
     public void testSocks4ProxyWithSplitResponse() throws Exception
     {
         int proxyPort = proxy.socket().getLocalPort();
-        client.getProxyConfiguration().getProxies().add(new Socks4Proxy("localhost", proxyPort));
+        client.getProxyConfiguration().addProxy(new Socks4Proxy("localhost", proxyPort));
 
         CountDownLatch latch = new CountDownLatch(1);
 
@@ -215,7 +215,7 @@ public class Socks4ProxyTest
             // The hostname must be that of the server, not of the proxy.
             ssl.setHostnameVerifier((hostname, session) -> serverHost.equals(hostname));
         });
-        client.getProxyConfiguration().getProxies().add(new Socks4Proxy(proxyHost, proxyPort));
+        client.getProxyConfiguration().addProxy(new Socks4Proxy(proxyHost, proxyPort));
 
         CountDownLatch latch = new CountDownLatch(1);
         client.newRequest(serverHost, serverPort)
@@ -283,7 +283,7 @@ public class Socks4ProxyTest
     {
         String proxyHost = "localhost";
         int proxyPort = proxy.socket().getLocalPort();
-        client.getProxyConfiguration().getProxies().add(new Socks4Proxy(proxyHost, proxyPort));
+        client.getProxyConfiguration().addProxy(new Socks4Proxy(proxyHost, proxyPort));
 
         long timeout = 1000;
         Request request = client.newRequest("localhost", proxyPort + 1)
@@ -305,7 +305,7 @@ public class Socks4ProxyTest
     {
         String proxyHost = "localhost";
         int proxyPort = proxy.socket().getLocalPort();
-        client.getProxyConfiguration().getProxies().add(new Socks4Proxy(proxyHost, proxyPort));
+        client.getProxyConfiguration().addProxy(new Socks4Proxy(proxyHost, proxyPort));
         long idleTimeout = 1000;
         client.setIdleTimeout(idleTimeout);
 
@@ -327,7 +327,7 @@ public class Socks4ProxyTest
     {
         String proxyHost = "localhost";
         int proxyPort = proxy.socket().getLocalPort();
-        client.getProxyConfiguration().getProxies().add(new Socks4Proxy(proxyHost, proxyPort));
+        client.getProxyConfiguration().addProxy(new Socks4Proxy(proxyHost, proxyPort));
 
         Request request = client.newRequest("localhost", proxyPort + 1);
         FutureResponseListener listener = new FutureResponseListener(request);
diff --git a/jetty-http2/http2-http-client-transport/src/test/java/org/eclipse/jetty/http2/client/http/HttpClientTransportOverHTTP2Test.java b/jetty-http2/http2-http-client-transport/src/test/java/org/eclipse/jetty/http2/client/http/HttpClientTransportOverHTTP2Test.java
index e8b6d01c9fe..dea91ece9fb 100644
--- a/jetty-http2/http2-http-client-transport/src/test/java/org/eclipse/jetty/http2/client/http/HttpClientTransportOverHTTP2Test.java
+++ b/jetty-http2/http2-http-client-transport/src/test/java/org/eclipse/jetty/http2/client/http/HttpClientTransportOverHTTP2Test.java
@@ -345,7 +345,7 @@ public class HttpClientTransportOverHTTP2Test extends AbstractTest
         });
 
         int proxyPort = connector.getLocalPort();
-        client.getProxyConfiguration().getProxies().add(new HttpProxy(new Origin.Address("localhost", proxyPort), false, new Origin.Protocol(List.of("h2c"), false)));
+        client.getProxyConfiguration().addProxy(new HttpProxy(new Origin.Address("localhost", proxyPort), false, new Origin.Protocol(List.of("h2c"), false)));
 
         int serverPort = proxyPort + 1; // Any port will do, just not the same as the proxy.
         ContentResponse response = client.newRequest("localhost", serverPort)
diff --git a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/AsyncMiddleManServletTest.java b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/AsyncMiddleManServletTest.java
index 554f7a12aba..5e7b212ed34 100644
--- a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/AsyncMiddleManServletTest.java
+++ b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/AsyncMiddleManServletTest.java
@@ -152,7 +152,7 @@ public class AsyncMiddleManServletTest
         clientPool.setName("client");
         client = new HttpClient();
         client.setExecutor(clientPool);
-        client.getProxyConfiguration().getProxies().add(new HttpProxy("localhost", proxyConnector.getLocalPort()));
+        client.getProxyConfiguration().addProxy(new HttpProxy("localhost", proxyConnector.getLocalPort()));
         client.start();
     }
 
diff --git a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ForwardProxyServerTest.java b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ForwardProxyServerTest.java
index 5cc07742f98..c3ec357d463 100644
--- a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ForwardProxyServerTest.java
+++ b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ForwardProxyServerTest.java
@@ -204,7 +204,7 @@ public class ForwardProxyServerTest
         ClientConnector clientConnector = new ClientConnector();
         clientConnector.setSslContextFactory(clientTLS);
         HttpClient httpClient = new HttpClient(new HttpClientTransportOverHTTP(clientConnector));
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         try
@@ -253,7 +253,7 @@ public class ForwardProxyServerTest
         });
 
         HttpClient httpClient = new HttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         ContentResponse response = httpClient.newRequest("[::1]", serverConnector.getLocalPort())
@@ -292,7 +292,7 @@ public class ForwardProxyServerTest
         });
 
         HttpClient httpClient = new HttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         ContentResponse response = httpClient.newRequest("[::1]", serverConnector.getLocalPort())
diff --git a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ForwardProxyTLSServerTest.java b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ForwardProxyTLSServerTest.java
index 9c190a99db0..0b25a646fef 100644
--- a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ForwardProxyTLSServerTest.java
+++ b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ForwardProxyTLSServerTest.java
@@ -197,7 +197,7 @@ public class ForwardProxyTLSServerTest
         startProxy(proxyTLS);
 
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         try
@@ -232,7 +232,7 @@ public class ForwardProxyTLSServerTest
         startProxy(proxyTLS);
 
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         try
@@ -279,7 +279,7 @@ public class ForwardProxyTLSServerTest
         startProxy(proxyTLS);
 
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         try
@@ -364,7 +364,7 @@ public class ForwardProxyTLSServerTest
         });
 
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         // Short idle timeout for HttpClient.
         httpClient.setIdleTimeout(idleTimeout);
         httpClient.start();
@@ -402,7 +402,7 @@ public class ForwardProxyTLSServerTest
         stopProxy();
 
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(new HttpProxy(new Origin.Address("localhost", proxyPort), proxySslContextFactory != null));
+        httpClient.getProxyConfiguration().addProxy(new HttpProxy(new Origin.Address("localhost", proxyPort), proxySslContextFactory != null));
         httpClient.start();
 
         ExecutionException x = assertThrows(ExecutionException.class, () ->
@@ -430,7 +430,7 @@ public class ForwardProxyTLSServerTest
         startProxy(proxyTLS);
 
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         assertThrows(ExecutionException.class, () ->
@@ -462,7 +462,7 @@ public class ForwardProxyTLSServerTest
         });
 
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         assertThrows(ExecutionException.class, () ->
@@ -485,7 +485,7 @@ public class ForwardProxyTLSServerTest
 
         HttpClient httpClient = newHttpClient();
         HttpProxy httpProxy = new HttpProxy(new Origin.Address("[::1]", proxyConnector.getLocalPort()), proxyTLS != null);
-        httpClient.getProxyConfiguration().getProxies().add(httpProxy);
+        httpClient.getProxyConfiguration().addProxy(httpProxy);
         httpClient.start();
 
         try
@@ -614,7 +614,7 @@ public class ForwardProxyTLSServerTest
         HttpProxy httpProxy = newHttpProxy();
         if (includeAddress)
             httpProxy.getIncludedAddresses().add("localhost:" + serverConnector.getLocalPort());
-        httpClient.getProxyConfiguration().getProxies().add(httpProxy);
+        httpClient.getProxyConfiguration().addProxy(httpProxy);
         URI uri = URI.create((proxySslContextFactory == null ? "http" : "https") + "://localhost:" + proxyConnector.getLocalPort());
         httpClient.getAuthenticationStore().addAuthentication(new BasicAuthentication(uri, realm, "proxyUser", "proxyPassword"));
         httpClient.start();
@@ -696,7 +696,7 @@ public class ForwardProxyTLSServerTest
         clientConnector.setSelectors(1);
         clientConnector.setSslContextFactory(clientSslContextFactory);
         HttpClient httpClient = new HttpClient(new HttpClientTransportOverHTTP(clientConnector));
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         try
@@ -767,7 +767,7 @@ public class ForwardProxyTLSServerTest
         proxyClientTLS.setEndpointIdentificationAlgorithm(null);
         proxyClientTLS.start();
         HttpProxy httpProxy = new HttpProxy(new Origin.Address("localhost", proxyConnector.getLocalPort()), proxyClientTLS);
-        httpClient.getProxyConfiguration().getProxies().add(httpProxy);
+        httpClient.getProxyConfiguration().addProxy(httpProxy);
         httpClient.start();
 
         try
@@ -798,7 +798,7 @@ public class ForwardProxyTLSServerTest
         startProxy(proxyTLS);
 
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.start();
 
         try
@@ -847,7 +847,7 @@ public class ForwardProxyTLSServerTest
         });
         startProxy(proxyTLS);
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.setConnectTimeout(timeout);
         httpClient.setIdleTimeout(4 * timeout);
         httpClient.start();
@@ -883,7 +883,7 @@ public class ForwardProxyTLSServerTest
         });
         startProxy(proxyTLS);
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.setConnectTimeout(timeout);
         // Short idle timeout for HttpClient.
         httpClient.setIdleTimeout(timeout);
@@ -929,7 +929,7 @@ public class ForwardProxyTLSServerTest
             }
         });
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(newHttpProxy());
+        httpClient.getProxyConfiguration().addProxy(newHttpProxy());
         httpClient.setConnectTimeout(timeout);
         httpClient.setIdleTimeout(10 * timeout);
         httpClient.start();
@@ -978,7 +978,7 @@ public class ForwardProxyTLSServerTest
         }
 
         HttpClient httpClient = newHttpClient();
-        httpClient.getProxyConfiguration().getProxies().add(new HttpProxy(proxyHost, proxyPort));
+        httpClient.getProxyConfiguration().addProxy(new HttpProxy(proxyHost, proxyPort));
         httpClient.start();
 
         try
diff --git a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletFailureTest.java b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletFailureTest.java
index b891224b89b..ae4ef350c38 100644
--- a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletFailureTest.java
+++ b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletFailureTest.java
@@ -117,7 +117,7 @@ public class ProxyServletFailureTest
         QueuedThreadPool executor = new QueuedThreadPool();
         executor.setName("client");
         result.setExecutor(executor);
-        result.getProxyConfiguration().getProxies().add(new HttpProxy("localhost", proxyConnector.getLocalPort()));
+        result.getProxyConfiguration().addProxy(new HttpProxy("localhost", proxyConnector.getLocalPort()));
         result.start();
         return result;
     }
diff --git a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletLoadTest.java b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletLoadTest.java
index 5fcc4e67766..5cad85f9f25 100644
--- a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletLoadTest.java
+++ b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletLoadTest.java
@@ -109,7 +109,7 @@ public class ProxyServletLoadTest
         clientPool.setName("client");
         HttpClient result = new HttpClient();
         result.setExecutor(clientPool);
-        result.getProxyConfiguration().getProxies().add(new HttpProxy("localhost", proxyConnector.getLocalPort()));
+        result.getProxyConfiguration().addProxy(new HttpProxy("localhost", proxyConnector.getLocalPort()));
         result.start();
         client = result;
     }
diff --git a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletTest.java b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletTest.java
index 7f804366de0..1a021a8985c 100644
--- a/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletTest.java
+++ b/jetty-proxy/src/test/java/org/eclipse/jetty/proxy/ProxyServletTest.java
@@ -62,6 +62,7 @@ import org.eclipse.jetty.client.ConnectionPool;
 import org.eclipse.jetty.client.HttpClient;
 import org.eclipse.jetty.client.HttpDestination;
 import org.eclipse.jetty.client.HttpProxy;
+import org.eclipse.jetty.client.ProxyConfiguration.Proxy;
 import org.eclipse.jetty.client.api.ContentResponse;
 import org.eclipse.jetty.client.api.Request;
 import org.eclipse.jetty.client.api.Response;
@@ -122,6 +123,7 @@ public class ProxyServletTest
     }
 
     private HttpClient client;
+    private Proxy clientProxy;
     private Server proxy;
     private ServerConnector proxyConnector;
     private ServletContextHandler proxyContext;
@@ -196,6 +198,7 @@ public class ProxyServletTest
 
     private void startClient(Consumer<HttpClient> consumer) throws Exception
     {
+        clientProxy = new HttpProxy("localhost", proxyConnector.getLocalPort());
         client = prepareClient(consumer);
     }
 
@@ -205,7 +208,7 @@ public class ProxyServletTest
         clientPool.setName("client");
         HttpClient result = new HttpClient();
         result.setExecutor(clientPool);
-        result.getProxyConfiguration().getProxies().add(new HttpProxy("localhost", proxyConnector.getLocalPort()));
+        result.getProxyConfiguration().addProxy(clientProxy);
         if (consumer != null)
             consumer.accept(result);
         result.start();
@@ -728,7 +731,7 @@ public class ProxyServletTest
         startProxy(proxyServletClass);
         startClient();
         int port = serverConnector.getLocalPort();
-        client.getProxyConfiguration().getProxies().get(0).getExcludedAddresses().add("127.0.0.1:" + port);
+        clientProxy.getExcludedAddresses().add("127.0.0.1:" + port);
 
         // Try with a proxied host
         ContentResponse response = client.newRequest("localhost", port)
diff --git a/jetty-unixdomain-server/src/test/java/org/eclipse/jetty/unixdomain/server/UnixDomainTest.java b/jetty-unixdomain-server/src/test/java/org/eclipse/jetty/unixdomain/server/UnixDomainTest.java
index d5f7417a071..a86dfc7215b 100644
--- a/jetty-unixdomain-server/src/test/java/org/eclipse/jetty/unixdomain/server/UnixDomainTest.java
+++ b/jetty-unixdomain-server/src/test/java/org/eclipse/jetty/unixdomain/server/UnixDomainTest.java
@@ -175,7 +175,7 @@ public class UnixDomainTest
         ClientConnector clientConnector = ClientConnector.forUnixDomain(unixDomainPath);
 
         HttpClient httpClient = new HttpClient(new HttpClientTransportDynamic(clientConnector));
-        httpClient.getProxyConfiguration().getProxies().add(new HttpProxy("localhost", fakeProxyPort));
+        httpClient.getProxyConfiguration().addProxy(new HttpProxy("localhost", fakeProxyPort));
         httpClient.start();
         try
         {
diff --git a/tests/test-http-client-transport/src/test/java/org/eclipse/jetty/http/client/HttpClientTransportDynamicTest.java b/tests/test-http-client-transport/src/test/java/org/eclipse/jetty/http/client/HttpClientTransportDynamicTest.java
index d349c23df5c..5844e0ee07b 100644
--- a/tests/test-http-client-transport/src/test/java/org/eclipse/jetty/http/client/HttpClientTransportDynamicTest.java
+++ b/tests/test-http-client-transport/src/test/java/org/eclipse/jetty/http/client/HttpClientTransportDynamicTest.java
@@ -586,7 +586,7 @@ public class HttpClientTransportDynamicTest
         int proxyPort = connector.getLocalPort();
         // The proxy speaks both http/1.1 and h2c.
         Origin.Protocol proxyProtocol = new Origin.Protocol(List.of("http/1.1", "h2c"), false);
-        client.getProxyConfiguration().getProxies().add(new HttpProxy(new Origin.Address("localhost", proxyPort), false, proxyProtocol));
+        client.getProxyConfiguration().addProxy(new HttpProxy(new Origin.Address("localhost", proxyPort), false, proxyProtocol));
 
         // Make an upgrade request from HTTP/1.1 to H2C.
         int serverPort = proxyPort + 1; // Any port will do.
diff --git a/tests/test-http-client-transport/src/test/java/org/eclipse/jetty/http/client/ProxyWithDynamicTransportTest.java b/tests/test-http-client-transport/src/test/java/org/eclipse/jetty/http/client/ProxyWithDynamicTransportTest.java
index 9852927687b..72283fd20b8 100644
--- a/tests/test-http-client-transport/src/test/java/org/eclipse/jetty/http/client/ProxyWithDynamicTransportTest.java
+++ b/tests/test-http-client-transport/src/test/java/org/eclipse/jetty/http/client/ProxyWithDynamicTransportTest.java
@@ -260,7 +260,7 @@ public class ProxyWithDynamicTransportTest
         int proxyPort = proxySecure ? proxyTLSConnector.getLocalPort() : proxyConnector.getLocalPort();
         Origin.Address proxyAddress = new Origin.Address("localhost", proxyPort);
         HttpProxy proxy = new HttpProxy(proxyAddress, proxySecure, proxyProtocol);
-        client.getProxyConfiguration().getProxies().add(proxy);
+        client.getProxyConfiguration().addProxy(proxy);
 
         String scheme = serverSecure ? "https" : "http";
         int serverPort = serverSecure ? serverTLSConnector.getLocalPort() : serverConnector.getLocalPort();
@@ -296,7 +296,7 @@ public class ProxyWithDynamicTransportTest
         int proxyPort = proxyConnector.getLocalPort();
         Origin.Address proxyAddress = new Origin.Address("localhost", proxyPort);
         HttpProxy proxy = new HttpProxy(proxyAddress, false, new Origin.Protocol(List.of("h2c"), false));
-        client.getProxyConfiguration().getProxies().add(proxy);
+        client.getProxyConfiguration().addProxy(proxy);
 
         long idleTimeout = 1000;
         http2Client.setStreamIdleTimeout(idleTimeout);
@@ -337,7 +337,7 @@ public class ProxyWithDynamicTransportTest
         int proxyPort = proxyConnector.getLocalPort();
         Origin.Address proxyAddress = new Origin.Address("localhost", proxyPort);
         HttpProxy httpProxy = new HttpProxy(proxyAddress, false, new Origin.Protocol(List.of("h2c"), false));
-        client.getProxyConfiguration().getProxies().add(httpProxy);
+        client.getProxyConfiguration().addProxy(httpProxy);
         proxy.stop();
 
         CountDownLatch latch = new CountDownLatch(1);
@@ -372,7 +372,7 @@ public class ProxyWithDynamicTransportTest
         int proxyPort = proxyConnector.getLocalPort();
         Origin.Address proxyAddress = new Origin.Address("localhost", proxyPort);
         HttpProxy httpProxy = new HttpProxy(proxyAddress, false, new Origin.Protocol(List.of("h2c"), false));
-        client.getProxyConfiguration().getProxies().add(httpProxy);
+        client.getProxyConfiguration().addProxy(httpProxy);
 
         CountDownLatch latch = new CountDownLatch(1);
         client.newRequest("localhost", serverConnector.getLocalPort())