diff --git a/openassessment/__init__.py b/openassessment/__init__.py
index e30468d86f..94916d98f8 100644
--- a/openassessment/__init__.py
+++ b/openassessment/__init__.py
@@ -2,4 +2,4 @@
 Initialization Information for Open Assessment Module
 """
 
-__version__ = '6.0.29'
+__version__ = '6.0.30'
diff --git a/openassessment/xblock/ui_mixins/mfe/submission_serializers.py b/openassessment/xblock/ui_mixins/mfe/submission_serializers.py
index 55ecbef919..8d60193037 100644
--- a/openassessment/xblock/ui_mixins/mfe/submission_serializers.py
+++ b/openassessment/xblock/ui_mixins/mfe/submission_serializers.py
@@ -136,7 +136,7 @@ class AddFileRequestSerializer(Serializer):
     fileDescription = CharField(source='description')
     fileName = CharField(source='name')
     fileSize = IntegerField(source='size', min_value=0)
-    contentType = CharField()
+    contentType = CharField(allow_blank=True)
 
 
 class FileUploadCallbackRequestSerializer(Serializer):
diff --git a/openassessment/xblock/ui_mixins/mfe/test_mfe_mixin.py b/openassessment/xblock/ui_mixins/mfe/test_mfe_mixin.py
index c8034cf76d..8d91f157ba 100644
--- a/openassessment/xblock/ui_mixins/mfe/test_mfe_mixin.py
+++ b/openassessment/xblock/ui_mixins/mfe/test_mfe_mixin.py
@@ -3,6 +3,7 @@
 """
 from collections import namedtuple
 from contextlib import contextmanager
+import copy
 import json
 from unittest.mock import Mock, PropertyMock, patch
 
@@ -727,7 +728,7 @@ def _mock_delete_uploaded_file(self, **kwargs):
             'fileName': 'n1',
             'fileSize': -1,
             'contentType': 'text',
-        }
+        },
     )
     @scenario("data/basic_scenario.xml")
     def test_bad_inputs(self, xblock, payload):
@@ -783,16 +784,22 @@ def test_upload_url_error(
         assert_error_response(resp, expected_status, expected_code, expected_context)
         mock_delete_file.assert_called_once_with(self.VALID_FILE_UPLOAD_OBJ.index)
 
+    @ddt.data(False, True)
     @scenario("data/basic_scenario.xml")
-    def test_upload_files(self, xblock):
+    def test_upload_files(self, xblock, blank_content_type):
         """ Test for file upload happy path"""
         url = 'www.someurl.xyz/fileUpload'
         mock_args = {
             'get_upload_url.return_value': url,
             'append_file_data.return_value': [self.VALID_FILE_UPLOAD_OBJ],
         }
+
+        payload = copy.deepcopy(self.VALID_FILE_UPLOAD_PAYLOAD)
+        if blank_content_type:
+            payload['contentType'] = ''
+
         with self._mock_submissions_actions(**mock_args):
-            resp = self.request_upload_files(xblock, self.VALID_FILE_UPLOAD_PAYLOAD)
+            resp = self.request_upload_files(xblock, payload)
         assert resp.status_code == 200
         assert resp.json == {
             'fileUrl': url,
diff --git a/package-lock.json b/package-lock.json
index a9527419b5..e84ea41c38 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "edx-ora2",
-  "version": "6.0.29",
+  "version": "6.0.30",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
diff --git a/package.json b/package.json
index a4b9c7d7fc..62a3390f9d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "edx-ora2",
-  "version": "6.0.29",
+  "version": "6.0.30",
   "repository": "https://github.com/openedx/edx-ora2.git",
   "dependencies": {
     "@edx/frontend-build": "8.0.6",