diff --git a/src/ifctester/ifctester/facet.py b/src/ifctester/ifctester/facet.py
index 28290f5dee..a47e7886e1 100644
--- a/src/ifctester/ifctester/facet.py
+++ b/src/ifctester/ifctester/facet.py
@@ -302,8 +302,8 @@ class Classification(Facet):
 
 
 class PartOf(Facet):
-    def __init__(self, entity=None, relation="IfcRelAggregates", minOccurs=None, maxOccurs=None, instructions=None):
-        self.parameters = ["entity", "@relation", "@minOccurs", "@maxOccurs", "@instructions"]
+    def __init__(self, entity=None, predefinedType=None, relation="IfcRelAggregates", minOccurs=None, maxOccurs=None, instructions=None):
+        self.parameters = ["entity", "predefinedType", "@relation", "@minOccurs", "@maxOccurs", "@instructions"]
         self.applicability_templates = [
             "An element with an {relation} relationship with an {entity}",
             "An element with an {relation} relationship",
@@ -312,7 +312,26 @@ class PartOf(Facet):
             "An element must have an {relation} relationship with an {entity}",
             "An element must have an {relation} relationship",
         ]
-        super().__init__(entity, relation, minOccurs, maxOccurs, instructions)
+        super().__init__(entity, predefinedType, relation, minOccurs, maxOccurs, instructions)
+
+    def asdict(self):
+        results = super().asdict()
+        entity = {}
+        if "entity" in results:
+            entity["name"] = results["entity"]
+            del results["entity"]
+        if "predefinedType" in results:
+            entity["predefinedType"] = results["predefinedType"]
+            del results["predefinedType"]
+        if entity:
+            results["entity"] = entity
+        return results
+
+    def parse(self, xml):
+        if "entity" in xml:
+            super().parse(xml["entity"])
+            del xml["entity"]
+        super().parse(xml)
 
     def __call__(self, inst, logger=None):
         if self.minOccurs == 0 and self.maxOccurs != 0:
@@ -330,7 +349,11 @@ class PartOf(Facet):
                 while aggregate is not None:
                     ancestors.append(aggregate.is_a())
                     if aggregate.is_a().upper() == self.entity:
-                        is_pass = True
+                        if self.predefinedType:
+                            if ifcopenshell.util.element.get_predefined_type(aggregate) == self.predefinedType:
+                                is_pass = True
+                        else:
+                            is_pass = True
                         break
                     aggregate = ifcopenshell.util.element.get_aggregate(aggregate)
                 if not is_pass:
@@ -348,6 +371,11 @@ class PartOf(Facet):
                 if group.is_a().upper() != self.entity:
                     is_pass = False
                     reason = {"type": "ENTITY", "actual": group.is_a().upper()}
+                if self.predefinedType:
+                    predefined_type = ifcopenshell.util.element.get_predefined_type(group)
+                    if predefined_type != self.predefinedType:
+                        is_pass = False
+                        reason = {"type": "PREDEFINEDTYPE", "actual": predefined_type}
         elif self.relation == "IfcRelContainedInSpatialStructure":
             container = ifcopenshell.util.element.get_container(inst)
             is_pass = container is not None
@@ -357,6 +385,11 @@ class PartOf(Facet):
                 if container.is_a().upper() != self.entity:
                     is_pass = False
                     reason = {"type": "ENTITY", "actual": container.is_a().upper()}
+                if self.predefinedType:
+                    predefined_type = ifcopenshell.util.element.get_predefined_type(container)
+                    if predefined_type != self.predefinedType:
+                        is_pass = False
+                        reason = {"type": "PREDEFINEDTYPE", "actual": predefined_type}
         elif self.relation == "IfcRelNests":
             nest = self.get_nested_whole(inst)
             is_pass = nest is not None
@@ -368,7 +401,11 @@ class PartOf(Facet):
                 while nest is not None:
                     ancestors.append(nest.is_a())
                     if nest.is_a().upper() == self.entity:
-                        is_pass = True
+                        if self.predefinedType:
+                            if ifcopenshell.util.element.get_predefined_type(nest) == self.predefinedType:
+                                is_pass = True
+                        else:
+                            is_pass = True
                         break
                     nest = self.get_nested_whole(nest)
                 if not is_pass:
diff --git a/src/ifctester/ifctester/ids.xsd b/src/ifctester/ifctester/ids.xsd
index 9a2bc9c39e..3aa6bbe4e2 100644
--- a/src/ifctester/ifctester/ids.xsd
+++ b/src/ifctester/ifctester/ids.xsd
@@ -1,6 +1,6 @@
-<!-- edited with XMLSpy v2022 (x64) (http://www.altova.com) by Leon van Berlo (Overleaf Investments B.V.) -->
-<!-- August 2, 2022 - DRAFT  -->
-<xs:schema xmlns:ids="http://standards.buildingsmart.org/IDS" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" targetNamespace="http://standards.buildingsmart.org/IDS" elementFormDefault="qualified" attributeFormDefault="unqualified" version="0.9.0">
+<!-- edited with XMLSpy v2022 (x64) (http://www.altova.com)  -->
+<!-- September 26, 2022 - DRAFT  -->
+<xs:schema xmlns:ids="http://standards.buildingsmart.org/IDS" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" targetNamespace="http://standards.buildingsmart.org/IDS" elementFormDefault="qualified" attributeFormDefault="unqualified" version="0.9.3">
 	<xs:import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="http://www.w3.org/2001/xml.xsd"/>
 	<xs:import namespace="http://www.w3.org/2001/XMLSchema" schemaLocation="https://www.w3.org/2001/XMLSchema.xsd"/>
 	<xs:import namespace="http://www.w3.org/2001/XMLSchema-instance" schemaLocation="http://www.w3.org/2001/XMLSchema-instance"/>
@@ -58,7 +58,7 @@
 	</xs:complexType>
 	<xs:complexType name="partOfType">
 		<xs:sequence>
-			<xs:element name="entity" type="ids:idsValue" minOccurs="0"/>
+			<xs:element name="entity" type="ids:entityType" minOccurs="0"/>
 		</xs:sequence>
 		<xs:attribute name="relation" type="ids:relations" use="required"/>
 	</xs:complexType>
@@ -198,7 +198,7 @@
 	<xs:complexType name="specificationType">
 		<xs:sequence>
 			<xs:element name="applicability" type="ids:applicabilityType"/>
-			<xs:element name="requirements">
+			<xs:element name="requirements" minOccurs="0">
 				<xs:complexType>
 					<xs:complexContent>
 						<xs:extension base="ids:requirementsType">
@@ -248,4 +248,4 @@
 			<xs:enumeration value="IfcRelNests"/>
 		</xs:restriction>
 	</xs:simpleType>
-</xs:schema>
+</xs:schema>
\ No newline at end of file
diff --git a/src/ifctester/test/test_facet.py b/src/ifctester/test/test_facet.py
index d80bba3feb..555d772b12 100644
--- a/src/ifctester/test/test_facet.py
+++ b/src/ifctester/test/test_facet.py
@@ -1404,13 +1404,17 @@ class TestPartOf:
         assert facet.asdict() == {"@relation": "IfcRelAggregates"}
         facet = PartOf(
             entity="IfcGroup",
+            predefinedType="predefinedType",
             relation="IfcRelAssignsToGroup",
             minOccurs="0",
             maxOccurs="unbounded",
             instructions="instructions",
         )
         assert facet.asdict() == {
-            "entity": {"simpleValue": "IfcGroup"},
+            "entity": {
+                "name": {"simpleValue": "IfcGroup"},
+                "predefinedType": {"simpleValue": "predefinedType"},
+            },
             "@relation": "IfcRelAssignsToGroup",
             "@minOccurs": "0",
             "@maxOccurs": "unbounded",
@@ -1446,6 +1450,12 @@ class TestPartOf:
         facet = PartOf(entity="IFCWALL", relation="IfcRelAggregates")
         run("An aggregate may specify the entity of the whole 2/2", facet=facet, inst=subelement, expected=False)
 
+        element.PredefinedType = "BASESLAB"
+        facet = PartOf(entity="IFCSLAB", predefinedType="BASESLAB", relation="IfcRelAggregates")
+        run("An aggregate may specify the predefined type of the whole 1/2", facet=facet, inst=subelement, expected=True)
+        facet = PartOf(entity="IFCSLAB", predefinedType="SLABRADOR", relation="IfcRelAggregates")
+        run("An aggregate may specify the predefined type of the whole 2/2", facet=facet, inst=subelement, expected=False)
+
         ifc = ifcopenshell.file()
         element = ifcopenshell.api.run("root.create_entity", ifc, ifc_class="IfcElementAssembly")
         subelement = ifcopenshell.api.run("root.create_entity", ifc, ifc_class="IfcSlab")
@@ -1472,6 +1482,12 @@ class TestPartOf:
         facet = PartOf(entity="IFCINVENTORY", relation="IfcRelAssignsToGroup")
         run("A group entity must match exactly 2/2", facet=facet, inst=element, expected=True)
 
+        group.ObjectType = "BUNNY"
+        facet = PartOf(entity="IFCINVENTORY", predefinedType="BUNNARY", relation="IfcRelAssignsToGroup")
+        run("A group predefined type must match exactly 2/2", facet=facet, inst=element, expected=False)
+        facet = PartOf(entity="IFCINVENTORY", predefinedType="BUNNY", relation="IfcRelAssignsToGroup")
+        run("A group predefined type must match exactly 2/2", facet=facet, inst=element, expected=True)
+
         ifc = ifcopenshell.file()
         element = ifcopenshell.api.run("root.create_entity", ifc, ifc_class="IfcElementAssembly")
         container = ifcopenshell.api.run("root.create_entity", ifc, ifc_class="IfcSpace")
@@ -1490,6 +1506,12 @@ class TestPartOf:
         facet = PartOf(relation="IfcRelContainedInSpatialStructure", entity="IFCSPACE")
         run("The container entity must match exactly 2/2", facet=facet, inst=element, expected=True)
 
+        container.ObjectType = "BURROW"
+        facet = PartOf(relation="IfcRelContainedInSpatialStructure", entity="IFCSPACE", predefinedType="WARREN")
+        run("The container predefined type must match exactly 1/2", facet=facet, inst=element, expected=False)
+        facet = PartOf(relation="IfcRelContainedInSpatialStructure", entity="IFCSPACE", predefinedType="BURROW")
+        run("The container predefined type must match exactly 2/2", facet=facet, inst=element, expected=True)
+
         ifc = ifcopenshell.file()
         element = ifcopenshell.api.run("root.create_entity", ifc, ifc_class="IfcSlab")
         subelement = ifcopenshell.api.run("root.create_entity", ifc, ifc_class="IfcBeam")
@@ -1516,6 +1538,12 @@ class TestPartOf:
         facet = PartOf(relation="IfcRelNests", entity="IFCFURNITURE")
         run("The nest entity must match exactly 2/2", facet=facet, inst=subelement, expected=True)
 
+        element.ObjectType = "WATERBOTTLE"
+        facet = PartOf(relation="IfcRelNests", entity="IFCFURNITURE", predefinedType="LITTERBOX")
+        run("The nest predefined type must match exactly 1/2", facet=facet, inst=subelement, expected=False)
+        facet = PartOf(relation="IfcRelNests", entity="IFCFURNITURE", predefinedType="WATERBOTTLE")
+        run("The nest predefined type must match exactly 2/2", facet=facet, inst=subelement, expected=True)
+
         ifc = ifcopenshell.file()
         element = ifcopenshell.api.run("root.create_entity", ifc, ifc_class="IfcFurniture")
         subelement = ifcopenshell.api.run("root.create_entity", ifc, ifc_class="IfcDiscreteAccessory")