diff --git a/lib/models/ObjectMD.js b/lib/models/ObjectMD.js
index b11a392af..e611d91bc 100644
--- a/lib/models/ObjectMD.js
+++ b/lib/models/ObjectMD.js
@@ -106,10 +106,12 @@ class ObjectMD {
             },
             'key': '',
             'location': null,
-            'isNull': '',
-            'nullVersionId': '',
-            'isDeleteMarker': '',
-            'versionId': undefined, // If no versionId, it should be undefined
+            // versionId, isNull, nullVersionId and isDeleteMarker
+            // should be undefined when not set explicitly
+            'isNull': undefined,
+            'nullVersionId': undefined,
+            'isDeleteMarker': undefined,
+            'versionId': undefined,
             'tags': {},
             'replicationInfo': {
                 status: '',
@@ -605,7 +607,7 @@ class ObjectMD {
      * @return {boolean} Whether new version is null or not
      */
     getIsNull() {
-        return this._data.isNull;
+        return this._data.isNull || false;
     }
 
     /**
@@ -622,7 +624,7 @@ class ObjectMD {
     /**
      * Get metadata nullVersionId value
      *
-     * @return {string} The version id of the null version
+     * @return {string|undefined} The version id of the null version
      */
     getNullVersionId() {
         return this._data.nullVersionId;
@@ -645,7 +647,7 @@ class ObjectMD {
      * @return {boolean} Whether object is a delete marker
      */
     getIsDeleteMarker() {
-        return this._data.isDeleteMarker;
+        return this._data.isDeleteMarker || false;
     }
 
     /**
@@ -662,7 +664,7 @@ class ObjectMD {
     /**
      * Get metadata versionId value
      *
-     * @return {string} The object versionId
+     * @return {string|undefined} The object versionId
      */
     getVersionId() {
         return this._data.versionId;
@@ -672,7 +674,7 @@ class ObjectMD {
      * Get metadata versionId value in encoded form (the one visible
      * to the S3 API user)
      *
-     * @return {string} The encoded object versionId
+     * @return {string|undefined} The encoded object versionId
      */
     getEncodedVersionId() {
         return VersionIDUtils.encode(this.getVersionId());
diff --git a/tests/unit/models/object.js b/tests/unit/models/object.js
index 9644b6b5e..ab49842d8 100644
--- a/tests/unit/models/object.js
+++ b/tests/unit/models/object.js
@@ -60,11 +60,11 @@ describe('ObjectMD class setters/getters', () => {
         ['Key', 'key'],
         ['Location', null, []],
         ['Location', ['location1']],
-        ['IsNull', null, ''],
+        ['IsNull', null, false],
         ['IsNull', true],
-        ['NullVersionId', null, ''],
+        ['NullVersionId', null, undefined],
         ['NullVersionId', '111111'],
-        ['IsDeleteMarker', null, ''],
+        ['IsDeleteMarker', null, false],
         ['IsDeleteMarker', true],
         ['VersionId', null, undefined],
         ['VersionId', '111111'],