diff --git a/playwright/src/main/java/com/microsoft/playwright/impl/Connection.java b/playwright/src/main/java/com/microsoft/playwright/impl/Connection.java
index 5a60cd98..657cbd64 100644
--- a/playwright/src/main/java/com/microsoft/playwright/impl/Connection.java
+++ b/playwright/src/main/java/com/microsoft/playwright/impl/Connection.java
@@ -36,6 +36,7 @@ import java.time.Duration;
 import java.util.HashMap;
 import java.util.Map;
 
+import static com.microsoft.playwright.impl.LoggingSupport.logWithTimestamp;
 import static com.microsoft.playwright.impl.Serialization.gson;
 
 class Message {
@@ -67,7 +68,11 @@ public class Connection {
   private int lastId = 0;
   private final Path srcDir;
   private final Map<Integer, WaitableResult<JsonElement>> callbacks = new HashMap<>();
-  private final boolean isLogging = "pw:channel".equals(System.getenv("DEBUG"));
+  private static final boolean isLogging;
+  static {
+    String debug = System.getenv("DEBUG");
+    isLogging = (debug != null) && debug.contains("pw:channel");
+  }
 
   class Root extends ChannelOwner {
     Root(Connection connection) {
@@ -156,7 +161,7 @@ public class Connection {
     }
     String messageString = gson().toJson(message);
     if (isLogging) {
-      System.err.println("SEND ► " + messageString);
+      logWithTimestamp("SEND ► " + messageString);
     }
     transport.send(messageString);
     return result;
@@ -190,7 +195,7 @@ public class Connection {
       return;
     }
     if (isLogging) {
-      System.err.println("◀ RECV " + messageString);
+      logWithTimestamp("◀ RECV " + messageString);
     }
     Gson gson = gson();
     Message message = gson.fromJson(messageString, Message.class);
diff --git a/playwright/src/main/java/com/microsoft/playwright/impl/LoggingSupport.java b/playwright/src/main/java/com/microsoft/playwright/impl/LoggingSupport.java
index 5b3387c7..768d168f 100644
--- a/playwright/src/main/java/com/microsoft/playwright/impl/LoggingSupport.java
+++ b/playwright/src/main/java/com/microsoft/playwright/impl/LoggingSupport.java
@@ -54,9 +54,14 @@ class LoggingSupport {
     }
   }
 
-  private void logApi(String message) {
+  static void logWithTimestamp(String message) {
     // This matches log format produced by the server.
     String timestamp = ZonedDateTime.now().format(timestampFormat);
-    System.err.println(timestamp + " pw:api " + message);
+    System.err.println(timestamp + " " + message);
+  }
+
+  private void logApi(String message) {
+    // This matches log format produced by the server.
+    System.err.println("pw:api " + message);
   }
 }
diff --git a/playwright/src/test/java/com/microsoft/playwright/TestChromium.java b/playwright/src/test/java/com/microsoft/playwright/TestChromium.java
index 9afdb343..052fb71d 100644
--- a/playwright/src/test/java/com/microsoft/playwright/TestChromium.java
+++ b/playwright/src/test/java/com/microsoft/playwright/TestChromium.java
@@ -41,6 +41,8 @@ public class TestChromium extends TestBase {
     // Do not create anything.
   }
 
+  private static int nextPort = 9339;
+
   private static String wsEndpointFromUrl(String urlString) throws IOException {
     URL url = new URL(urlString);
     URLConnection request = url.openConnection();
@@ -52,7 +54,7 @@ public class TestChromium extends TestBase {
 
   @Test
   void shouldConnectToAnExistingCdpSession() throws IOException {
-    int port = 9339;
+    int port = nextPort++;
     try (Browser browserServer = browserType.launch(createLaunchOptions()
         .setArgs(asList("--remote-debugging-port=" + port)))) {
       Browser cdpBrowser = browserType.connectOverCDP("http://localhost:" + port);
@@ -64,7 +66,7 @@ public class TestChromium extends TestBase {
 
   @Test
   void shouldConnectToAnExistingCdpSessionTwice() throws IOException {
-    int port = 9339;
+    int port = nextPort++;
     try (Browser browserServer = browserType.launch(createLaunchOptions()
         .setArgs(asList("--remote-debugging-port=" + port)))) {
       String endpointUrl = "http://localhost:" + port;
@@ -90,7 +92,7 @@ public class TestChromium extends TestBase {
 
   @Test
   void shouldConnectOverAWsEndpoint() throws IOException {
-    int port = 9339;
+    int port = nextPort++;
     try (Browser browserServer = browserType.launch(createLaunchOptions()
         .setArgs(asList("--remote-debugging-port=" + port)))) {
       String wsEndpoint = wsEndpointFromUrl("http://localhost:" + port + "/json/version/");
diff --git a/playwright/src/test/java/com/microsoft/playwright/WebSocketServerImpl.java b/playwright/src/test/java/com/microsoft/playwright/WebSocketServerImpl.java
index cd864ab9..a274b56b 100644
--- a/playwright/src/test/java/com/microsoft/playwright/WebSocketServerImpl.java
+++ b/playwright/src/test/java/com/microsoft/playwright/WebSocketServerImpl.java
@@ -22,15 +22,19 @@ import org.java_websocket.server.WebSocketServer;
 
 import java.net.InetSocketAddress;
 import java.util.concurrent.Semaphore;
+import java.util.concurrent.atomic.AtomicInteger;
 
 class WebSocketServerImpl extends WebSocketServer implements AutoCloseable {
   volatile ClientHandshake lastClientHandshake;
   private final Semaphore startSemaphore = new Semaphore(0);
 
-  static final int WS_SERVER_PORT = 8910;
+  private static final AtomicInteger nextWsServerPort = new AtomicInteger(8910);
 
   static WebSocketServerImpl create() throws InterruptedException {
-    WebSocketServerImpl result = new WebSocketServerImpl(new InetSocketAddress("localhost", WebSocketServerImpl.WS_SERVER_PORT));
+    // FIXME: WebSocketServer.stop() doesn't release socket immediately and starting another server
+    // fails with "Address already in use", so we just allocate new port.
+    int port = nextWsServerPort.getAndIncrement();
+    WebSocketServerImpl result = new WebSocketServerImpl(new InetSocketAddress("localhost", port));
     result.start();
     result.startSemaphore.acquire();
     return result;
@@ -61,6 +65,8 @@ class WebSocketServerImpl extends WebSocketServer implements AutoCloseable {
 
   @Override
   public void onError(WebSocket webSocket, Exception e) {
+    e.printStackTrace();
+    startSemaphore.release();
   }
 
   @Override