diff --git a/integrationtests/test.py b/integrationtests/test.py
index 782687be27863e479186717d698b9965f7be8c64..36f1546f029bbf31e2563c7bbfabdbdf3e62e36b 100755
--- a/integrationtests/test.py
+++ b/integrationtests/test.py
@@ -53,12 +53,12 @@ def main(args):
     ident_adapt.register_identifiable(
         "Person", db.RecordType()
         .add_parent(name="Person")
-        .add_property(name="first_name")
+        #.add_property(name="first_name")
         .add_property(name="last_name"))
     ident_adapt.register_identifiable(
         "Measurement", db.RecordType()
         .add_parent(name="Measurement")
-        .add_property(name="identifier")
+        #.add_property(name="identifier")
         .add_property(name="date")
         .add_property(name="project"))
     ident_adapt.register_identifiable(
@@ -75,6 +75,15 @@ def main(args):
     assert len(ins) == 18
     assert len(ups) == 0
 
+    # Do a second run on the same data, there should be no changes:
+    crawler = Crawler(debug=True, identifiableAdapter=ident_adapt)
+    crawler.copy_attributes = Mock()
+    crawler.crawl_directory(rfp("../unittests/test_directories", "examples_article"),
+                            rfp("../unittests/scifolder_cfood.yml"))
+    ins, ups = crawler.synchronize()
+    assert len(ins) == 0
+    assert len(ups) == 0
+
 
 def parse_args():
     parser = argparse.ArgumentParser(description=__doc__,