diff --git a/src/ifcgeom/kernels/opencascade/IfcGeomShapes.cpp b/src/ifcgeom/kernels/opencascade/IfcGeomShapes.cpp
index 08d1d6a09e..09c10dd964 100644
--- a/src/ifcgeom/kernels/opencascade/IfcGeomShapes.cpp
+++ b/src/ifcgeom/kernels/opencascade/IfcGeomShapes.cpp
@@ -824,16 +824,16 @@ bool OpenCascadeKernel::convert_impl(const taxonomy::extrusion* extrusion, ifcop
 	return true;
 }
 
-bool OpenCascadeKernel::convert_impl(const taxonomy::shell *extrusion, ifcopenshell::geometry::ConversionResults& results) {
+bool OpenCascadeKernel::convert_impl(const taxonomy::shell *shell, ifcopenshell::geometry::ConversionResults& results) {
 	TopoDS_Shape shape;
-	if (!convert(extrusion, shape)) {
+	if (!convert(shell, shape)) {
 		return false;
 	}
 	results.emplace_back(ConversionResult(
-		extrusion->instance->data().id(),
-		extrusion->matrix,
+		shell->instance->data().id(),
+		shell->matrix,
 		new OpenCascadeShape(shape),
-		extrusion->surface_style
+		shell->surface_style
 	));
 	return true;
 }
diff --git a/src/ifcgeom/schema/bind_convert_decl.i b/src/ifcgeom/schema/bind_convert_decl.i
index b612616039..212c4e822d 100644
--- a/src/ifcgeom/schema/bind_convert_decl.i
+++ b/src/ifcgeom/schema/bind_convert_decl.i
@@ -2,6 +2,6 @@
 #undef BIND
 #endif
 
-#define BIND(T) ifcopenshell::geometry::taxonomy::item* map(const IfcSchema::T*);
+#define BIND(T) ifcopenshell::geometry::taxonomy::item* map_impl(const IfcSchema::T*);
 
 #include "mapping.i"
diff --git a/src/ifcgeom/schema/bind_convert_impl.i b/src/ifcgeom/schema/bind_convert_impl.i
index 5914425f88..298c809e0e 100644
--- a/src/ifcgeom/schema/bind_convert_impl.i
+++ b/src/ifcgeom/schema/bind_convert_impl.i
@@ -5,7 +5,7 @@
 #define BIND(T) \
 	if (l->declaration().is(IfcSchema::T::Class())) { \
 		try { \
-			taxonomy::item* item = map((IfcSchema::T*)l); \
+			taxonomy::item* item = map_impl((IfcSchema::T*)l); \
 			if (item != nullptr) { \
 				item->instance = l; \
 				try { \
diff --git a/src/ifcgeom/schema/mapping.cpp b/src/ifcgeom/schema/mapping.cpp
index 3218e4355b..689a539f27 100644
--- a/src/ifcgeom/schema/mapping.cpp
+++ b/src/ifcgeom/schema/mapping.cpp
@@ -144,7 +144,7 @@ namespace {
 	}
 };
 
-taxonomy::item* mapping::map(const IfcSchema::IfcExtrudedAreaSolid* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcExtrudedAreaSolid* inst) {
 	// @todo length unit
 	return new taxonomy::extrusion(
 		as<taxonomy::matrix4>(map(inst->Position())),
@@ -154,19 +154,19 @@ taxonomy::item* mapping::map(const IfcSchema::IfcExtrudedAreaSolid* inst) {
 	);
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcRepresentation* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcRepresentation* inst) {
 	return map_to_collection(this, inst->Items());
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcFaceBasedSurfaceModel* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcFaceBasedSurfaceModel* inst) {
 	return map_to_collection(this, inst->FbsmFaces());
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcConnectedFaceSet* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcConnectedFaceSet* inst) {
 	return map_to_collection<taxonomy::shell>(this, inst->CfsFaces());
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcFace* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcFace* inst) {
 	taxonomy::face* face = new taxonomy::face;
 	auto bounds = inst->Bounds();
 	for (auto& bound : *bounds) {
@@ -184,7 +184,7 @@ taxonomy::item* mapping::map(const IfcSchema::IfcFace* inst) {
 	return face;
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcPolyLoop* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcPolyLoop* inst) {
 	taxonomy::loop* loop = new taxonomy::loop;
 	
 	taxonomy::point3 first, previous;
@@ -218,7 +218,7 @@ taxonomy::item* mapping::map(const IfcSchema::IfcPolyLoop* inst) {
 	return loop;
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcCartesianPoint* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcCartesianPoint* inst) {
 	auto coords = inst->Coordinates();
 	return new taxonomy::point3(
 		coords.size() >= 1 ? coords[0] : 0.,
@@ -227,38 +227,38 @@ taxonomy::item* mapping::map(const IfcSchema::IfcCartesianPoint* inst) {
 	);
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcProduct* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcProduct* inst) {
 	auto n = new taxonomy::node;
 	n->matrix = as<taxonomy::matrix4>(map(inst->ObjectPlacement()));
 	return n;
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcAxis2Placement3D* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcAxis2Placement3D* inst) {
 	// @todo length unit
 	return new taxonomy::matrix4();
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcCartesianTransformationOperator2DnonUniform* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcCartesianTransformationOperator2DnonUniform* inst) {
 	// @todo length unit
 	return new taxonomy::matrix4();
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcCartesianTransformationOperator3DnonUniform* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcCartesianTransformationOperator3DnonUniform* inst) {
 	// @todo length unit
 	return new taxonomy::matrix4();
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcCartesianTransformationOperator2D* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcCartesianTransformationOperator2D* inst) {
 	// @todo length unit
 	return new taxonomy::matrix4();
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcCartesianTransformationOperator3D* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcCartesianTransformationOperator3D* inst) {
 	// @todo length unit
 	return new taxonomy::matrix4();
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcLocalPlacement* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcLocalPlacement* inst) {
 	// @todo length unit
 	return new taxonomy::matrix4();
 }
@@ -672,7 +672,7 @@ namespace {
 	}
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcMaterial* material) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcMaterial* material) {
 	IfcSchema::IfcMaterialDefinitionRepresentation::list::ptr defs = material->HasRepresentation();
 	for (IfcSchema::IfcMaterialDefinitionRepresentation::list::it jt = defs->begin(); jt != defs->end(); ++jt) {
 		IfcSchema::IfcRepresentation::list::ptr reps = (*jt)->Representations();
@@ -693,7 +693,7 @@ taxonomy::item* mapping::map(const IfcSchema::IfcMaterial* material) {
 	// return &(style_cache[material->data().id()] = material_style);
 }
 
-taxonomy::item* mapping::map(const IfcSchema::IfcStyledItem* inst) {
+taxonomy::item* mapping::map_impl(const IfcSchema::IfcStyledItem* inst) {
 	static taxonomy::colour white = taxonomy::colour(1., 1., 1.);
 
 	taxonomy::style* surface_style = new taxonomy::style;