diff --git a/jdk/test/java/util/stream/test/org/openjdk/tests/java/util/stream/CollectorsTest.java b/jdk/test/java/util/stream/test/org/openjdk/tests/java/util/stream/CollectorsTest.java
index 18ba487edec..08d731dc96e 100644
--- a/jdk/test/java/util/stream/test/org/openjdk/tests/java/util/stream/CollectorsTest.java
+++ b/jdk/test/java/util/stream/test/org/openjdk/tests/java/util/stream/CollectorsTest.java
@@ -517,7 +517,7 @@ public class CollectorsTest extends OpTestCase {
                                                                                new ToListAssertion<>())));
     }
 
-    @Test
+    @Test(groups = { "serialization-hostile" })
     public void testFlatMappingClose() {
         Function<Integer, Integer> classifier = i -> i;
         AtomicInteger ai = new AtomicInteger();