diff --git a/tests/test_issues.py b/tests/test_issues.py
new file mode 100644
index 0000000000000000000000000000000000000000..c2d3a438b4d45abab17ba2f5f3d76362a8ce6137
--- /dev/null
+++ b/tests/test_issues.py
@@ -0,0 +1,81 @@
+# -*- coding: utf-8 -*-
+#
+# ** header v3.0
+# This file is a part of the CaosDB Project.
+#
+# Copyright (c) 2020 IndiScale GmbH
+# Copyright (c) 2020 Daniel Hornung <d.hornung@indiscale.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+# ** end header
+
+"""Tests for issues on gitlab.com"""
+
+from __future__ import absolute_import, print_function, unicode_literals
+
+import caosdb as db
+from caosdb.exceptions import (AmbiguityException, CaosDBException,
+                               EntityDoesNotExistError, EntityError,
+                               TransactionError, UniqueNamesError)
+from nose import with_setup
+from nose.tools import (assert_equal, assert_false, assert_is_none,
+                        assert_is_not_none, assert_raises, assert_true,
+                        nottest)
+
+from tests import test_misc
+
+
+def setup_module():
+    try:
+        db.execute_query("FIND ENTITY WITH ID > 100").delete()
+    except Exception as delete_exc:
+        print(delete_exc)
+
+
+def setup():
+    """No setup required."""
+    pass
+
+
+def teardown():
+    """Deleting entities again."""
+    setup_module()
+
+
+# ########################### Issue tests start here ###########################
+
+@with_setup(setup, teardown)
+def test_issue_85():
+    """SQLIntegrityConstraintViolationException for special inheritance patterns.
+
+    Tests for https://gitlab.com/caosdb/caosdb-server/-/issues/85
+    """
+    A = db.RecordType(name="A")
+    B = db.RecordType(name="B")
+    C = db.RecordType(name="C")
+
+    B.add_parent(A)
+
+    # This order is important for the test to fail.
+    C.add_parent(B)
+    C.add_parent(C)
+    C.add_parent(A)
+
+    c = db.Container()
+    # c.extend([C, B, A])  # worked before #86 was fixed
+    # c.extend([C, A, B])  # worked before #86 was fixed
+    c.extend([B, C, A])    # insert() failed before #86 was fixed
+    c.insert()  # Raised java.sql.SQLIntegrityConstraintViolationException:
+                # Duplicate entry '12345-12346-12345' for key 'PRIMARY'