diff --git a/unittests/table_json_conversion/data/simple_data_additional.xlsx b/unittests/table_json_conversion/data/simple_data_additional.xlsx
new file mode 100644
index 0000000000000000000000000000000000000000..53a2fb491a793691066bf7c81e8dba840fd8d8f1
Binary files /dev/null and b/unittests/table_json_conversion/data/simple_data_additional.xlsx differ
diff --git a/unittests/table_json_conversion/data/simple_data_wrong_types.xlsx b/unittests/table_json_conversion/data/simple_data_wrong_types.xlsx
new file mode 100644
index 0000000000000000000000000000000000000000..a28ea48ffa0dfc9f24560a6adc9bc7c7f3157320
Binary files /dev/null and b/unittests/table_json_conversion/data/simple_data_wrong_types.xlsx differ
diff --git a/unittests/table_json_conversion/test_read_xlsx.py b/unittests/table_json_conversion/test_read_xlsx.py
index 17574d8af4116a1a2318fbf694d41b4033fbfa47..8b13eacd1c64751afea3029501631f028c58897a 100644
--- a/unittests/table_json_conversion/test_read_xlsx.py
+++ b/unittests/table_json_conversion/test_read_xlsx.py
@@ -114,6 +114,9 @@ def test_faulty_foreign():
     # Simple wrong foreign key
     converter = convert.XLSXConverter(xlsx=rfp("data/simple_data_wrong_foreign.xlsx"),
                                       schema=rfp("data/simple_schema.json"))
+    from IPython import embed
+    embed()
+
     with pytest.raises(RuntimeError):
         converter.to_dict()
     errors = converter.get_errors()