diff --git a/src/newcrawler/converters.py b/src/newcrawler/converters.py
index 79ee17dcc6232d214144a19b9a79d6948b45e3ab..3b7c1d7d9795d7769503cbcd1f9437cbef8e16f8 100644
--- a/src/newcrawler/converters.py
+++ b/src/newcrawler/converters.py
@@ -96,6 +96,9 @@ def handle_value(value: Union[dict, str], values: GeneralStore):
     if match is not None:
         varname = match.group("varname")
         if varname in values:
+            if values[varname] is None:
+                propvalue = None
+                return (propvalue, collection_mode)
             if isinstance(values[varname], db.Entity):
                 propvalue = values[varname]
                 return (propvalue, collection_mode)
diff --git a/src/newcrawler/crawl.py b/src/newcrawler/crawl.py
index be4a997c39a5977b878813dffec31eec3f1ad0bc..de350a2aa96546d29825646caffc4b7a4940171e 100644
--- a/src/newcrawler/crawl.py
+++ b/src/newcrawler/crawl.py
@@ -769,6 +769,7 @@ class Crawler(object):
             updateList)
 
         # remove unnecessary updates from list
+        # TODO: refactoring of typo
         for el in to_be_updated:
             self.replace_entities_by_ids(el)
 
diff --git a/unittests/test_tool.py b/unittests/test_tool.py
index dd9fb83d772496cc6b3729f2893997360d318f18..404d04f1c6da9b2c423f4709a9057dd6efd25ac8 100755
--- a/unittests/test_tool.py
+++ b/unittests/test_tool.py
@@ -249,6 +249,8 @@ def test_crawler_update_list(crawler, ident):
 
 def test_synchronization(crawler, ident):
     insl, updl = crawler.synchronize(commit_changes=False)
+    # breakpoint()
+    # ident.check_record(ident.get_records()[1], insl[0])
     assert len(insl) == 0
     assert len(updl) == 0