diff --git a/playwright/src/test/java/com/microsoft/playwright/TestPageNetworkResponse.java b/playwright/src/test/java/com/microsoft/playwright/TestPageNetworkResponse.java
index 816bb73c..7d6abfcd 100644
--- a/playwright/src/test/java/com/microsoft/playwright/TestPageNetworkResponse.java
+++ b/playwright/src/test/java/com/microsoft/playwright/TestPageNetworkResponse.java
@@ -56,6 +56,7 @@ public class TestPageNetworkResponse extends TestBase {
       exchange.sendResponseHeaders(200, 0);
       OutputStreamWriter writer = new OutputStreamWriter(exchange.getResponseBody());
       writer.write("hello ");
+      writer.flush();
     });
 
     // send request and wait for server response
@@ -80,6 +81,7 @@ public class TestPageNetworkResponse extends TestBase {
       exchange.sendResponseHeaders(200, 0);
       OutputStreamWriter writer = new OutputStreamWriter(exchange.getResponseBody());
       writer.write("hello ");
+      writer.flush();
     });
 
     // send request and wait for server response