diff --git a/src/ifcexpressparser/bootstrap.py b/src/ifcexpressparser/bootstrap.py
index 5d9ff3997e..41e2d5270c 100644
--- a/src/ifcexpressparser/bootstrap.py
+++ b/src/ifcexpressparser/bootstrap.py
@@ -114,6 +114,7 @@ actions = {
     'aggregation_types'         : "lambda t: AggregationType(t)",
     'general_aggregation_types' : "lambda t: AggregationType(t)",
     'select_type'               : "lambda t: SelectType(t)",
+    'binary_type'               : "lambda t: BinaryType(t)",
     'subtype_declaration'       : "lambda t: SubtypeExpression(t)",
     'derive_clause'             : "lambda t: AttributeList('derive', t)",
     'derived_attr'              : "lambda t: DerivedAttribute(t)",
diff --git a/src/ifcexpressparser/mapping.py b/src/ifcexpressparser/mapping.py
index fcebef7744..8e5f02f928 100644
--- a/src/ifcexpressparser/mapping.py
+++ b/src/ifcexpressparser/mapping.py
@@ -77,7 +77,7 @@ class Mapping:
     def make_argument_entity(self, attr):
         type = attr.type if hasattr(attr, 'type') else attr
         while isinstance(type, nodes.AggregationType): type = type.type
-        if type in self.express_to_cpp_typemapping: return "Type::UNDEFINED"
+        if str(type) in self.express_to_cpp_typemapping: return "Type::UNDEFINED"
         else: return "Type::%s" % type        
 
     def make_argument_type(self, attr):
@@ -88,6 +88,8 @@ class Mapping:
                 return "ENTITY_INSTANCE"
             elif self.schema.is_type(type):
                 return _make_argument_type(self.schema.types[type].type.type)
+            elif isinstance(type, nodes.BinaryType):
+                return "BINARY"
             elif isinstance(type, nodes.EnumerationType):
                 return "ENUMERATION"
             elif isinstance(type, nodes.AggregationType):
diff --git a/src/ifcexpressparser/nodes.py b/src/ifcexpressparser/nodes.py
index 3bf6753dc8..d21a29df67 100644
--- a/src/ifcexpressparser/nodes.py
+++ b/src/ifcexpressparser/nodes.py
@@ -145,6 +145,13 @@ class DerivedAttribute(Node):
         return str(self.name)
 
 
+class BinaryType(Node):
+    def init(self):
+        pass
+    def __repr__(self):
+        return "binary"
+
+
 class BoundSpecification(Node):
     lower = property(lambda self: self.tokens[1])
     upper = property(lambda self: self.tokens[3])
diff --git a/src/ifcparse/Ifc4.cpp b/src/ifcparse/Ifc4.cpp
index 8486f5b3fb..f8c2b7433e 100644
--- a/src/ifcparse/Ifc4.cpp
+++ b/src/ifcparse/Ifc4.cpp
@@ -7366,8 +7366,8 @@ bool IfcPropertySetDefinitionSet::is(Type::Enum v) const { return v == IfcProper
 Type::Enum IfcPropertySetDefinitionSet::type() const { return Type::IfcPropertySetDefinitionSet; }
 Type::Enum IfcPropertySetDefinitionSet::Class() { return Type::IfcPropertySetDefinitionSet; }
 IfcPropertySetDefinitionSet::IfcPropertySetDefinitionSet(IfcAbstractEntity* e) { entity = e; }
-IfcPropertySetDefinitionSet::IfcPropertySetDefinitionSet(IfcTemplatedEntityList< IfcPropertySetDefinition >::ptr v) { IfcWritableEntity* e = new IfcWritableEntity(Type::IfcPropertySetDefinitionSet); e->setArgument(0, v); entity = e; }
-IfcPropertySetDefinitionSet::operator IfcTemplatedEntityList< IfcPropertySetDefinition >::ptr() const { return *entity->getArgument(0); }
+IfcPropertySetDefinitionSet::IfcPropertySetDefinitionSet(IfcTemplatedEntityList< IfcPropertySetDefinition >::ptr v) { IfcWritableEntity* e = new IfcWritableEntity(Type::IfcPropertySetDefinitionSet); e->setArgument(0, v->generalize()); entity = e; }
+IfcPropertySetDefinitionSet::operator IfcTemplatedEntityList< IfcPropertySetDefinition >::ptr() const { IfcEntityList::ptr es = *entity->getArgument(0); return es->as<IfcPropertySetDefinition>(); }
 
 // Function implementations for IfcRadioActivityMeasure
 IfcUtil::ArgumentType IfcRadioActivityMeasure::getArgumentType(unsigned int i) const { if (i == 0) { return IfcUtil::Argument_DOUBLE; } else { throw IfcParse::IfcException("argument out of range"); } }