diff --git a/data-prepper-plugins/s3-source/src/main/java/org/opensearch/dataprepper/plugins/source/S3ScanPartitionCreationSupplier.java b/data-prepper-plugins/s3-source/src/main/java/org/opensearch/dataprepper/plugins/source/S3ScanPartitionCreationSupplier.java
index 5ec4848354..8f1de687ad 100644
--- a/data-prepper-plugins/s3-source/src/main/java/org/opensearch/dataprepper/plugins/source/S3ScanPartitionCreationSupplier.java
+++ b/data-prepper-plugins/s3-source/src/main/java/org/opensearch/dataprepper/plugins/source/S3ScanPartitionCreationSupplier.java
@@ -101,7 +101,7 @@ private List<PartitionIdentifier> listFilteredS3ObjectsForBucket(final List<Stri
                                                                      final LocalDateTime endDateTime,
                                                                      final Map<String, Object> globalStateMap) {
 
-        Instant mostRecentLastModifiedTimestamp = globalStateMap.containsKey(bucket) ? Instant.parse((String) globalStateMap.get(bucket)) : null;
+        Instant mostRecentLastModifiedTimestamp = globalStateMap.get(bucket) != null ? Instant.parse((String) globalStateMap.get(bucket)) : null;
         final List<PartitionIdentifier> allPartitionIdentifiers = new ArrayList<>();
         ListObjectsV2Response listObjectsV2Response = null;
         do {
diff --git a/data-prepper-plugins/s3-source/src/test/java/org/opensearch/dataprepper/plugins/source/S3ScanPartitionCreationSupplierTest.java b/data-prepper-plugins/s3-source/src/test/java/org/opensearch/dataprepper/plugins/source/S3ScanPartitionCreationSupplierTest.java
index 40a9501766..5d161562d2 100644
--- a/data-prepper-plugins/s3-source/src/test/java/org/opensearch/dataprepper/plugins/source/S3ScanPartitionCreationSupplierTest.java
+++ b/data-prepper-plugins/s3-source/src/test/java/org/opensearch/dataprepper/plugins/source/S3ScanPartitionCreationSupplierTest.java
@@ -147,6 +147,8 @@ void getNextPartition_supplier_without_scheduling_options_returns_expected_Parti
         assertThat(globalStateMap.containsKey(SCAN_COUNT), equalTo(true));
         assertThat(globalStateMap.get(SCAN_COUNT), equalTo(1));
 
+        globalStateMap.put(secondBucket, null);
+
         assertThat(partitionCreationSupplier.apply(globalStateMap), equalTo(Collections.emptyList()));
 
         assertThat(resultingPartitions, notNullValue());