diff --git a/rdmo/core/constants.py b/rdmo/core/constants.py
index e0c6fccd74..1e1cbc3a78 100644
--- a/rdmo/core/constants.py
+++ b/rdmo/core/constants.py
@@ -60,6 +60,7 @@
 }
 
 HUMAN2BYTES_MAPPER = {
+    "b": {"base": 1000, "power": 0},
     "kb": {"base": 1000, "power": 1},
     "k": {"base": 1000, "power": 1},
     "mb": {"base": 1000, "power": 2},
diff --git a/rdmo/projects/tests/test_validator_quota.py b/rdmo/projects/tests/test_validator_quota.py
index f700287cac..4eee080e26 100644
--- a/rdmo/projects/tests/test_validator_quota.py
+++ b/rdmo/projects/tests/test_validator_quota.py
@@ -9,7 +9,7 @@
 attribute_path = attribute__path='individual/single/text'
 
 
-def test_serializer_create_file(db):
+def test_serializer_create_file(db, settings):
     class MockedProject:
         file_size = 1
 
@@ -17,6 +17,8 @@ class MockedView:
         action = 'create'
         project = MockedProject()
 
+    settings.PROJECT_FILE_QUOTA = '1b'
+
     validator = ValueQuotaValidator()
     serializer = ValueSerializer()
     serializer.context['view'] = MockedView()
@@ -63,3 +65,22 @@ class MockedView:
     validator({
         'value_type': 'text'
     }, serializer)
+
+
+def test_serializer_update(db, settings):
+    class MockedProject:
+        file_size = 1
+
+    class MockedView:
+        action = 'update'
+        project = MockedProject()
+
+    settings.PROJECT_FILE_QUOTA = '0'
+
+    validator = ValueQuotaValidator()
+    serializer = ValueSerializer()
+    serializer.context['view'] = MockedView()
+
+    validator({
+        'value_type': 'file'
+    }, serializer)