diff --git a/jetty-websocket/jetty-websocket-tests/src/test/java/org/eclipse/jetty/websocket/tests/client/ClientConnectTest.java b/jetty-websocket/jetty-websocket-tests/src/test/java/org/eclipse/jetty/websocket/tests/client/ClientConnectTest.java
index 597af68b6f2..2f9988dcaae 100644
--- a/jetty-websocket/jetty-websocket-tests/src/test/java/org/eclipse/jetty/websocket/tests/client/ClientConnectTest.java
+++ b/jetty-websocket/jetty-websocket-tests/src/test/java/org/eclipse/jetty/websocket/tests/client/ClientConnectTest.java
@@ -26,6 +26,8 @@ import java.net.SocketTimeoutException;
 import java.net.URI;
 import java.time.Duration;
 import java.util.EnumSet;
+import java.util.List;
+import java.util.Map;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
@@ -182,6 +184,27 @@ public class ClientConnectTest
         }
     }
 
+    @Test
+    public void testUpgradeRequest_PercentEncodedQuery() throws Exception
+    {
+        CloseTrackingEndpoint cliSock = new CloseTrackingEndpoint();
+        client.setIdleTimeout(Duration.ofSeconds(10));
+
+        URI wsUri = WSURI.toWebsocket(server.getURI().resolve("/echo?name=%25foo"));
+        ClientUpgradeRequest request = new ClientUpgradeRequest();
+        request.setSubProtocols("echo");
+        Future<Session> future = client.connect(cliSock, wsUri);
+
+        try (Session sess = future.get(30, TimeUnit.SECONDS))
+        {
+            assertThat("Connect.UpgradeRequest", sess.getUpgradeRequest(), notNullValue());
+            Map<String, List<String>> paramMap = sess.getUpgradeRequest().getParameterMap();
+            List<String> values = paramMap.get("name");
+            assertThat("Params[name]", values.get(0), is("%foo"));
+            assertThat("Connect.UpgradeResponse", sess.getUpgradeResponse(), notNullValue());
+        }
+    }
+
     @Test
     public void testUpgradeWithAuthorizationHeader() throws Exception
     {
diff --git a/jetty-websocket/websocket-core/src/main/java/org/eclipse/jetty/websocket/core/internal/Negotiated.java b/jetty-websocket/websocket-core/src/main/java/org/eclipse/jetty/websocket/core/internal/Negotiated.java
index 269fdb8f1a1..17cdaf294a4 100644
--- a/jetty-websocket/websocket-core/src/main/java/org/eclipse/jetty/websocket/core/internal/Negotiated.java
+++ b/jetty-websocket/websocket-core/src/main/java/org/eclipse/jetty/websocket/core/internal/Negotiated.java
@@ -28,6 +28,7 @@ import java.util.Objects;
 import java.util.stream.Collectors;
 
 import org.eclipse.jetty.util.MultiMap;
+import org.eclipse.jetty.util.StringUtil;
 import org.eclipse.jetty.util.UrlEncoded;
 import org.eclipse.jetty.websocket.core.ExtensionConfig;
 import org.eclipse.jetty.websocket.core.WebSocketConstants;
@@ -50,14 +51,17 @@ public class Negotiated
         this.extensions = extensions;
         this.protocolVersion = protocolVersion;
 
+        String rawQuery = requestURI.getRawQuery();
         Map<String, List<String>> map;
-        if (requestURI.getQuery() == null)
+        if (StringUtil.isBlank(rawQuery))
+        {
             map = Collections.emptyMap();
+        }
         else
         {
             map = new HashMap<>();
             MultiMap<String> params = new MultiMap<>();
-            UrlEncoded.decodeUtf8To(requestURI.getQuery(), params);
+            UrlEncoded.decodeUtf8To(rawQuery, params);
             for (String p : params.keySet())
             {
                 map.put(p, Collections.unmodifiableList(params.getValues(p)));