diff --git a/langstream-e2e-tests/src/test/java/ai/langstream/tests/PythonAgentsIT.java b/langstream-e2e-tests/src/test/java/ai/langstream/tests/PythonAgentsIT.java
index bfb324b48..3a3880b2b 100644
--- a/langstream-e2e-tests/src/test/java/ai/langstream/tests/PythonAgentsIT.java
+++ b/langstream-e2e-tests/src/test/java/ai/langstream/tests/PythonAgentsIT.java
@@ -24,6 +24,7 @@
 import org.junit.jupiter.api.Tag;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
+import org.testcontainers.shaded.com.google.common.base.Strings;
 
 @Slf4j
 @ExtendWith(BaseEndToEndTest.class)
@@ -115,8 +116,12 @@ public void testSource() {
                                 .formatted(applicationId)
                                 .split(" "));
         log.info("Output: {}", output);
+        String bigPayload = Strings.repeat("test", 10000);
         Assertions.assertTrue(
-                output.contains("{\"record\":{\"key\":null,\"value\":\"test\",\"headers\":{}}"));
+                output.contains(
+                        "{\"record\":{\"key\":null,\"value\":\""
+                                + bigPayload
+                                + "\",\"headers\":{}}"));
 
         deleteAppAndAwaitCleanup(tenant, applicationId);
     }
diff --git a/langstream-e2e-tests/src/test/resources/apps/python-source/python/example.py b/langstream-e2e-tests/src/test/resources/apps/python-source/python/example.py
index c6f20a98b..ef4e63292 100644
--- a/langstream-e2e-tests/src/test/resources/apps/python-source/python/example.py
+++ b/langstream-e2e-tests/src/test/resources/apps/python-source/python/example.py
@@ -26,7 +26,7 @@ def read(self):
         if not self.sent:
             logging.info("Sending the record")
             self.sent = True
-            return [SimpleRecord("test")]
+            return [SimpleRecord("test" * 10000)]
         return []
 
     def commit(self, records):