diff --git a/src/main/kotlin/org/opensearch/replication/task/index/IndexReplicationTask.kt b/src/main/kotlin/org/opensearch/replication/task/index/IndexReplicationTask.kt
index b4662aa3..b0af5a54 100644
--- a/src/main/kotlin/org/opensearch/replication/task/index/IndexReplicationTask.kt
+++ b/src/main/kotlin/org/opensearch/replication/task/index/IndexReplicationTask.kt
@@ -401,12 +401,9 @@ open class IndexReplicationTask(id: Long, type: String, action: String, descript
         }
     }
 
-    private suspend fun UpdateFollowereMapping(followerIndex: String,mappingSource: String) {
+    private suspend fun updateFollowerMapping(followerIndex: String,mappingSource: String?) {
 
         val options = IndicesOptions.strictSingleIndexNoExpandForbidClosed()
-        if (null == mappingSource) {
-            throw MappingNotAvailableException("MappingSource is not available")
-        }
         val putMappingRequest = PutMappingRequest().indices(followerIndex).indicesOptions(options)
             .source(mappingSource, XContentType.JSON)
         val updateMappingRequest = UpdateMetadataRequest(followerIndex, UpdateMetadataRequest.Type.MAPPING, putMappingRequest)
@@ -557,19 +554,20 @@ open class IndexReplicationTask(id: Long, type: String, action: String, descript
                 val options = IndicesOptions.strictSingleIndexNoExpandForbidClosed()
                 var gmr = GetMappingsRequest().indices(this.leaderIndex.name).indicesOptions(options)
                 var mappingResponse = remoteClient.suspending(remoteClient.admin().indices()::getMappings, injectSecurityContext = true)(gmr)
-                var leaderMappingSource = mappingResponse.mappings.get(this.leaderIndex.name).source().toString()
-                val leaderProperties = mappingResponse.mappings().get(this.leaderIndex.name).sourceAsMap().toMap().get("properties") as Map<String,Any>
+                var leaderMappingSource = mappingResponse?.mappings?.get(this.leaderIndex.name)?.source()?.toString()
+                @Suppress("UNCHECKED_CAST")
+                val leaderProperties = mappingResponse?.mappings()?.get(this.leaderIndex.name)?.sourceAsMap()?.toMap()?.get("properties") as? Map<String,Any>?
                 gmr = GetMappingsRequest().indices(this.followerIndexName).indicesOptions(options)
                 mappingResponse = client.suspending(client.admin().indices()::getMappings, injectSecurityContext = true)(gmr)
-                val followerProperties = mappingResponse.mappings().get(this.followerIndexName).sourceAsMap().toMap().get("properties") as Map<String,Any>
-                for(iter in followerProperties) {
-                    if(leaderProperties.containsKey(iter.key) && leaderProperties.getValue(iter.key).toString()!=(iter.value).toString()){
-                        log.info("Updating Multi-field Mapping at Follower")
-                        UpdateFollowereMapping(this.followerIndexName,leaderMappingSource)
-                        break;
+                @Suppress("UNCHECKED_CAST")
+                val followerProperties = mappingResponse?.mappings()?.get(this.followerIndexName)?.sourceAsMap()?.toMap()?.get("properties") as? Map<String,Any>?
+                for((key,value) in followerProperties?: emptyMap()) {
+                    if (leaderProperties?.getValue(key).toString() != (value).toString()) {
+                        log.debug("Updating Multi-field Mapping at Follower")
+                        updateFollowerMapping(this.followerIndexName, leaderMappingSource)
+                        break
                     }
                 }
-
             } catch (e: Exception) {
                 log.error("Error in getting the required metadata ${e.stackTraceToString()}")
             } finally {