diff --git a/src/ifcopenshell-python/test/fixtures/ColumnPSetsOfSets.ifc b/src/ifcopenshell-python/test/fixtures/ColumnPSetsOfSets.ifc
new file mode 100644
index 0000000000..26394a29b3
--- /dev/null
+++ b/src/ifcopenshell-python/test/fixtures/ColumnPSetsOfSets.ifc
@@ -0,0 +1,145 @@
+ISO-10303-21;
+HEADER;
+FILE_DESCRIPTION(('ViewDefinition [CoordinationView]','RevitIdentifiers [ContentGUID: a0df3484-2dab-42c5-b806-8c10d313bee0, VersionGUID: 658c1394-f3a4-43d1-9b3c-eee44a0cd67a, NumberOfSaves: 2]','CoordinateReference [CoordinateBase: Shared Coordinates]'),'2;1');
+FILE_NAME('Column_4x3.ifc','2025-03-12T13:53:30+00:00',(''),(''),'ODA SDAI 24.12','Autodesk Revit 25.4.0.32 (ENG) - IFC 25.4.0.32','');
+FILE_SCHEMA(('IFC4X3_ADD2'));
+ENDSEC;
+DATA;
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+#43=IFCPROPERTYSINGLEVALUE('Reference',$,IFCIDENTIFIER('Project Information'),$);
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+#105=IFCPROPERTYSINGLEVALUE('Reference',$,IFCIDENTIFIER('Circle Head - Project Datum'),$);
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+#119=IFCPROPERTYSINGLEVALUE('NumberOfStoreys',$,IFCCOUNTMEASURE(1),$);
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+#134=IFCUNITASSIGNMENT((#19,#62,#63));
+#135=IFCPROPERTYSINGLEVALUE('Label',$,IFCLABEL('Pset 1'),$);
+#136=IFCPROPERTYSET('2n2HQdKqzYK7QnaOEEelxy',$,'PSet_1',$,(#135));
+#137=IFCPROPERTYSINGLEVALUE('Label',$,IFCLABEL('Pset 2'),$);
+#138=IFCPROPERTYSET('2n2HQdKqzYK7QnaOEEelxz',$,'PSet_2',$,(#137));
+#139=IFCRELDEFINESBYPROPERTIES('2n2HQdKqzYK7QnaOEEelzz',$,$,$,(#93),IFCPROPERTYSETDEFINITIONSET((#136,#138)));
+ENDSEC;
+END-ISO-10303-21;
diff --git a/src/ifcopenshell-python/test/test_streaming_rocksdb_and_simpletyperefs.py b/src/ifcopenshell-python/test/test_streaming_rocksdb_and_simpletyperefs.py
new file mode 100644
index 0000000000..5cb3fccf85
--- /dev/null
+++ b/src/ifcopenshell-python/test/test_streaming_rocksdb_and_simpletyperefs.py
@@ -0,0 +1,63 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Thomas Krijnen <thomas@aecgeeks.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import gc
+import os
+import struct
+import pytest
+import ifcopenshell
+import tempfile
+
+fn = os.path.join(os.path.dirname(__file__), "fixtures/ColumnPSetsOfSets.ifc")
+
+
+def test_stream():
+    assert next(filter(lambda d: d.get("id") == 139, ifcopenshell.stream2(fn)))["RelatingPropertyDefinition"] == {
+        "type": "IfcPropertySetDefinitionSet",
+        "value": ({"ref": 136}, {"ref": 138}),
+    }
+
+
+def test_file():
+    f = ifcopenshell.open(fn)
+    assert f[139].RelatingPropertyDefinition.is_a("IfcPropertySetDefinitionSet")
+    assert {x.id() for x in f[139].RelatingPropertyDefinition[0]} == {136, 138}
+
+
+def test_rocks():
+    with tempfile.TemporaryDirectory() as d:
+        rfn = os.path.join(d, os.path.basename(fn))
+        ifcopenshell.convert_path_to_rocksdb(fn, rfn)
+
+        assert os.path.exists(rfn)
+
+        f = ifcopenshell.open(rfn)
+        assert f[139].RelatingPropertyDefinition.is_a("IfcPropertySetDefinitionSet")
+        assert {x.id() for x in f[139].RelatingPropertyDefinition[0]} == {136, 138}
+
+        b = f.wrapped_data.key_value_store_query("i|139|5")[2:]
+        iden = struct.unpack("Q", b)[0]
+        b = f.wrapped_data.key_value_store_query(f"t|{iden}|0")[1:]
+        assert set(struct.unpack("Q", b[i : i + 8])[0] for i in range(1, len(b), 9)) == {136, 138}
+
+        del f
+        gc.collect()
+
+
+if __name__ == "__main__":
+    pytest.main(["-sx", __file__])