diff --git a/interop-testing/src/main/java/io/grpc/testing/integration/AbstractInteropTest.java b/interop-testing/src/main/java/io/grpc/testing/integration/AbstractInteropTest.java
index 60a72b5f8d..b0d656f7de 100644
--- a/interop-testing/src/main/java/io/grpc/testing/integration/AbstractInteropTest.java
+++ b/interop-testing/src/main/java/io/grpc/testing/integration/AbstractInteropTest.java
@@ -790,6 +790,8 @@ public abstract class AbstractInteropTest {
         = asyncStub.fullDuplexCall(responseObserver);
     requestObserver.onCompleted();
     responseObserver.awaitCompletion(operationTimeoutMillis(), TimeUnit.MILLISECONDS);
+    assertSuccess(responseObserver);
+    assertTrue("Expected an empty stream", responseObserver.getValues().isEmpty());
   }
 
   @Test