diff --git a/server/src/test/java/org/opensearch/index/mapper/FlatObjectFieldMapperTests.java b/server/src/test/java/org/opensearch/index/mapper/FlatObjectFieldMapperTests.java
index 637072c8886c1..5b5ca378ee7ff 100644
--- a/server/src/test/java/org/opensearch/index/mapper/FlatObjectFieldMapperTests.java
+++ b/server/src/test/java/org/opensearch/index/mapper/FlatObjectFieldMapperTests.java
@@ -25,7 +25,6 @@
 
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.core.IsEqual.equalTo;
-import static org.hamcrest.core.StringContains.containsString;
 
 public class FlatObjectFieldMapperTests extends MapperTestCase {
     private static final String FIELD_TYPE = "flat_object";
@@ -133,9 +132,10 @@ public void testDefaults() throws Exception {
 
     public void testNullValue() throws IOException {
         DocumentMapper mapper = createDocumentMapper(fieldMapping(this::minimalMapping));
-        MapperParsingException e = expectThrows(MapperParsingException.class, () -> mapper.parse(source(b -> b.nullField("field"))));
-        assertThat(e.getMessage(), containsString("object mapping for [_doc] tried to parse field [field] as object"));
-
+        ParsedDocument parsedDocument = mapper.parse(source(b -> b.nullField("field")));
+        assertEquals(1, parsedDocument.docs().size());
+        IndexableField[] fields = parsedDocument.rootDoc().getFields("field");
+        assertEquals(0, fields.length);
     }
 
     @Override