diff --git a/common/src/main/java/org/opensearch/ml/common/input/nlp/TextDocsMLInput.java b/common/src/main/java/org/opensearch/ml/common/input/nlp/TextDocsMLInput.java
index ec9e31b3a9..deeb5ef81f 100644
--- a/common/src/main/java/org/opensearch/ml/common/input/nlp/TextDocsMLInput.java
+++ b/common/src/main/java/org/opensearch/ml/common/input/nlp/TextDocsMLInput.java
@@ -114,7 +114,11 @@ public TextDocsMLInput(XContentParser parser, FunctionName functionName) throws
                 case TEXT_DOCS_FIELD:
                     ensureExpectedToken(XContentParser.Token.START_ARRAY, parser.currentToken(), parser);
                     while (parser.nextToken() != XContentParser.Token.END_ARRAY) {
-                        docs.add(parser.text());
+                        if (parser.currentToken() == null || parser.currentToken() == XContentParser.Token.VALUE_NULL) {
+                            docs.add(null);
+                        } else {
+                            docs.add(parser.text());
+                        }
                     }
                     break;
                 case RESULT_FILTER_FIELD:
diff --git a/common/src/test/java/org/opensearch/ml/common/input/nlp/TextDocsMLInputTest.java b/common/src/test/java/org/opensearch/ml/common/input/nlp/TextDocsMLInputTest.java
index 6578cd42bd..ec00aef17f 100644
--- a/common/src/test/java/org/opensearch/ml/common/input/nlp/TextDocsMLInputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/input/nlp/TextDocsMLInputTest.java
@@ -24,6 +24,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 public class TextDocsMLInputTest {
@@ -47,22 +48,22 @@ public void parseTextDocsMLInput() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         input.toXContent(builder, ToXContent.EMPTY_PARAMS);
         String jsonStr = builder.toString();
-        parseMLInput(jsonStr);
+        parseMLInput(jsonStr, 2);
     }
 
     @Test
     public void parseTextDocsMLInput_OldWay() throws IOException {
-        String jsonStr = "{\"text_docs\": [ \"doc1\", \"doc2\" ],\"return_number\": true, \"return_bytes\": true,\"target_response\": [ \"field1\" ], \"target_response_positions\": [2]}";
-        parseMLInput(jsonStr);
+        String jsonStr = "{\"text_docs\": [ \"doc1\", \"doc2\", null ],\"return_number\": true, \"return_bytes\": true,\"target_response\": [ \"field1\" ], \"target_response_positions\": [2]}";
+        parseMLInput(jsonStr, 3);
     }
 
     @Test
     public void parseTextDocsMLInput_NewWay() throws IOException {
         String jsonStr = "{\"text_docs\":[\"doc1\",\"doc2\"],\"result_filter\":{\"return_bytes\":true,\"return_number\":true,\"target_response\":[\"field1\"], \"target_response_positions\": [2]}}";
-        parseMLInput(jsonStr);
+        parseMLInput(jsonStr, 2);
     }
 
-    private void parseMLInput(String jsonStr) throws IOException {
+    private void parseMLInput(String jsonStr, int docSize) throws IOException {
         XContentParser parser = XContentType.JSON.xContent().createParser(new NamedXContentRegistry(new SearchModule(Settings.EMPTY,
                 Collections.emptyList()).getNamedXContents()), null, jsonStr);
         parser.nextToken();
@@ -72,9 +73,12 @@ private void parseMLInput(String jsonStr) throws IOException {
         assertEquals(input.getFunctionName(), parsedInput.getFunctionName());
         assertEquals(input.getInputDataset().getInputDataType(), parsedInput.getInputDataset().getInputDataType());
         TextDocsInputDataSet inputDataset = (TextDocsInputDataSet) parsedInput.getInputDataset();
-        assertEquals(2, inputDataset.getDocs().size());
+        assertEquals(docSize, inputDataset.getDocs().size());
         assertEquals("doc1", inputDataset.getDocs().get(0));
         assertEquals("doc2", inputDataset.getDocs().get(1));
+        if (inputDataset.getDocs().size() > 2) {
+            assertNull(inputDataset.getDocs().get(2));
+        }
         assertNotNull(inputDataset.getResultFilter());
         assertTrue(inputDataset.getResultFilter().isReturnBytes());
         assertTrue(inputDataset.getResultFilter().isReturnNumber());