diff --git a/server/src/test/java/org/opensearch/index/IndexServiceTests.java b/server/src/test/java/org/opensearch/index/IndexServiceTests.java
index 1b8e1abb1bf1b..a9fc108f6addb 100644
--- a/server/src/test/java/org/opensearch/index/IndexServiceTests.java
+++ b/server/src/test/java/org/opensearch/index/IndexServiceTests.java
@@ -33,7 +33,9 @@
 package org.opensearch.index;
 
 import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.SortField;
 import org.apache.lucene.search.TopDocs;
+import org.opensearch.Version;
 import org.opensearch.action.support.ActiveShardCount;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.compress.CompressedXContent;
@@ -526,4 +528,60 @@ public void testUpdateRemoteTranslogBufferIntervalDynamically() {
         indexMetadata = client().admin().cluster().prepareState().execute().actionGet().getState().metadata().index("test");
         assertEquals("20s", indexMetadata.getSettings().get(IndexSettings.INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey()));
     }
+
+    public void testIndexSort() {
+        Settings settings = Settings.builder()
+            .put(IndexSettings.INDEX_TRANSLOG_SYNC_INTERVAL_SETTING.getKey(), "0ms") // disable
+            .putList("index.sort.field", "sortfield")
+            .build();
+        try {
+            // Integer index sort should be remained to int sort type
+            IndexService index = createIndex("test", settings, createTestMapping("integer"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.INT);
+
+            // Long index sort should be remained to long sort type
+            index = createIndex("test", settings, createTestMapping("long"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.LONG);
+
+            // String index sort should be remained to string sort type
+            index = createIndex("test", settings, createTestMapping("string"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.STRING);
+        } catch (IllegalArgumentException ex) {
+            assertEquals("failed to parse value [0ms] for setting [index.translog.sync_interval], must be >= [100ms]", ex.getMessage());
+        }
+    }
+
+    public void testIndexSortBackwardCompatible() {
+        Settings settings = Settings.builder()
+            .put(IndexSettings.INDEX_TRANSLOG_SYNC_INTERVAL_SETTING.getKey(), "0ms") // disable
+            .put(IndexMetadata.SETTING_INDEX_VERSION_CREATED.getKey(), Version.V_2_6_1)
+            .putList("index.sort.field", "sortfield")
+            .build();
+        try {
+            // Integer index sort should be converted to long sort type
+            IndexService index = createIndex("test", settings, createTestMapping("integer"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.LONG);
+
+            // Long index sort should be remained to long sort type
+            index = createIndex("test", settings, createTestMapping("long"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.LONG);
+
+            // String index sort should be remained to string sort type
+            index = createIndex("test", settings, createTestMapping("string"));
+            assertTrue(index.getIndexSortSupplier().get().getSort()[0].getType() == SortField.Type.STRING);
+        } catch (IllegalArgumentException ex) {
+            assertEquals("failed to parse value [0ms] for setting [index.translog.sync_interval], must be >= [100ms]", ex.getMessage());
+        }
+    }
+
+    private static String createTestMapping(String type) {
+        return "  \"properties\": {\n"
+            + "    \"test\": {\n"
+            + "      \"type\": \"text\"\n"
+            + "    },\n"
+            + "    \"sortfield\": {\n"
+            + "      \"type\": \" + type + \"\n"
+            + "    }\n"
+            + "  }";
+    }
 }