diff --git a/src/main/kotlin/org/opensearch/commons/alerting/model/DataSources.kt b/src/main/kotlin/org/opensearch/commons/alerting/model/DataSources.kt
index 110cf36f..7757a0b3 100644
--- a/src/main/kotlin/org/opensearch/commons/alerting/model/DataSources.kt
+++ b/src/main/kotlin/org/opensearch/commons/alerting/model/DataSources.kt
@@ -32,10 +32,10 @@ data class DataSources(
     val alertsHistoryIndexPattern: String? = "<.opendistro-alerting-alert-history-{now/d}-1>", // AlertIndices.ALERT_HISTORY_INDEX_PATTERN
 
     /** Configures a custom index alias to store comments associated with alerts.*/
-    val commentsIndex: String? = ".opensearch-alerting-comments-history-write", // CommentsIndices.COMMENTS_HISTORY_WRITE_INDEX
+    val commentsIndex: String? = DEFAULT_COMMENTS_INDEX, // CommentsIndices.COMMENTS_HISTORY_WRITE_INDEX
 
     /** Configures a custom index pattern for commentsIndex alias.*/
-    val commentsIndexPattern: String? = "<.opensearch-alerting-comments-history-{now/d}-1>", // CommentsIndices.COMMENTS_HISTORY_INDEX_PATTERN
+    val commentsIndexPattern: String? = DEFAULT_COMMENTS_INDEX_PATTERN, // CommentsIndices.COMMENTS_HISTORY_INDEX_PATTERN
 
     /** Configures custom mappings by field type for query index.
      * Custom query index mappings are configurable, only if a custom query index is configured too. */
@@ -102,8 +102,8 @@ data class DataSources(
         alertsIndex = alertsIndex,
         alertsHistoryIndex = alertsHistoryIndex,
         alertsHistoryIndexPattern = alertsHistoryIndexPattern,
-        commentsIndex = null,
-        commentsIndexPattern = null,
+        commentsIndex = DEFAULT_COMMENTS_INDEX,
+        commentsIndexPattern = DEFAULT_COMMENTS_INDEX_PATTERN,
         queryIndexMappingsByType = queryIndexMappingsByType,
         findingsEnabled = findingsEnabled
     )
@@ -152,6 +152,9 @@ data class DataSources(
         const val QUERY_INDEX_MAPPINGS_BY_TYPE = "query_index_mappings_by_type"
         const val FINDINGS_ENABLED_FIELD = "findings_enabled"
 
+        const val DEFAULT_COMMENTS_INDEX = ".opensearch-alerting-comments-history-write"
+        const val DEFAULT_COMMENTS_INDEX_PATTERN = "<.opensearch-alerting-comments-history-{now/d}-1>"
+
         @JvmStatic
         @Throws(IOException::class)
         @Suppress("UNCHECKED_CAST")
diff --git a/src/test/kotlin/org/opensearch/commons/alerting/model/XContentTests.kt b/src/test/kotlin/org/opensearch/commons/alerting/model/XContentTests.kt
index ffb76105..3ce1f041 100644
--- a/src/test/kotlin/org/opensearch/commons/alerting/model/XContentTests.kt
+++ b/src/test/kotlin/org/opensearch/commons/alerting/model/XContentTests.kt
@@ -574,4 +574,23 @@ class XContentTests {
         val parsedDocLevelMonitorInput = parsedRemoteDocLevelMonitorInput.docLevelMonitorInput
         assertEquals("Round tripping RemoteDocLevelMonitorInput doesn't work", docLevelMonitorInput, parsedDocLevelMonitorInput)
     }
+
+    @Test
+    fun `test DataSources parsing`() {
+        val dataSources = DataSources(
+            ScheduledJob.DOC_LEVEL_QUERIES_INDEX,
+            ".opensearch-alerting-finding-history-write",
+            "<.opensearch-alerting-finding-history-{now/d}-1>",
+            ".opendistro-alerting-alerts",
+            ".opendistro-alerting-alert-history-write",
+            "<.opendistro-alerting-alert-history-{now/d}-1>",
+            mapOf(),
+            false
+        )
+        Assertions.assertNotNull(dataSources)
+
+        val dataSourcesString = dataSources.toXContent(builder(), ToXContent.EMPTY_PARAMS).string()
+        val parsedDataSources = DataSources.parse(parser(dataSourcesString))
+        Assertions.assertEquals(dataSources, parsedDataSources, "Round tripping DataSources doesn't work")
+    }
 }