diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 60294c2256..c451f0cc45 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -221,7 +221,7 @@ endif()
 
 if(GLTF_SUPPORT OR CITYJSON_SUPPORT)
     UNIFY_ENVVARS_AND_CACHE(JSON_INCLUDE_DIR)
-    find_path(json_header_path "json.hpp" ${JSON_INCLUDE_DIR} PATH_SUFFIXES "nlohmann")
+    find_path(json_header_path "nlohmann/json.hpp" ${JSON_INCLUDE_DIR})
     set(JSON_INCLUDE_DIR ${json_header_path})
 
     if(json_header_path)
diff --git a/src/examples/IfcAdvancedHouse.cpp b/src/examples/IfcAdvancedHouse.cpp
index cb1f64975f..f4623fa7cc 100644
--- a/src/examples/IfcAdvancedHouse.cpp
+++ b/src/examples/IfcAdvancedHouse.cpp
@@ -38,7 +38,7 @@
 
 #include <Standard_Version.hxx>
 
-#define IfcSchema Ifc2x3
+#define IfcSchema Ifc4
 #include "../ifcparse/macros.h"
 #include "../ifcparse/Ifc2x3.h"
 #include "../ifcparse/IfcBaseClass.h"
diff --git a/src/examples/IfcOpenHouse.cpp b/src/examples/IfcOpenHouse.cpp
index 3f6d56236d..f7e4a85873 100644
--- a/src/examples/IfcOpenHouse.cpp
+++ b/src/examples/IfcOpenHouse.cpp
@@ -35,7 +35,7 @@
 
 #include <Precision.hxx>
 
-#define IfcSchema Ifc2x3
+#define IfcSchema Ifc4
 #include "../ifcparse/macros.h"
 #include "../ifcparse/Ifc2x3.h"
 #include "../ifcparse/IfcBaseClass.h"
diff --git a/src/ifcconvert/validation_utils.h b/src/ifcconvert/validation_utils.h
index 0b9484df3c..c8801d6537 100644
--- a/src/ifcconvert/validation_utils.h
+++ b/src/ifcconvert/validation_utils.h
@@ -471,7 +471,7 @@ struct intersection_validator {
 			}
 
 			std::stringstream ss;
-			ss << geom_object->product()->data().toString();
+			geom_object->product()->toString(ss);
 			auto sss = ss.str();
 			std::wcout << sss.c_str() << std::endl;
 
diff --git a/src/serializers/GltfSerializer.cpp b/src/serializers/GltfSerializer.cpp
index c5b4d4c776..4dbfd003e1 100644
--- a/src/serializers/GltfSerializer.cpp
+++ b/src/serializers/GltfSerializer.cpp
@@ -451,29 +451,29 @@ void GltfSerializer::setFile(IfcParse::IfcFile* f) {
 	}
 	if (coordops) {
 		for (auto& coordop : *coordops) {
-			IfcUtil::IfcBaseClass* source_crs = *coordop->as<IfcUtil::IfcBaseEntity>()->get("SourceCRS");
+			IfcUtil::IfcBaseClass* source_crs = coordop->as<IfcUtil::IfcBaseEntity>()->get("SourceCRS");
 			if (source_crs->declaration().is("IfcGeometricRepresentationContext")) {
-				IfcUtil::IfcBaseClass* target_crs = *coordop->as<IfcUtil::IfcBaseEntity>()->get("TargetCRS");
+				IfcUtil::IfcBaseClass* target_crs = coordop->as<IfcUtil::IfcBaseEntity>()->get("TargetCRS");
 				auto name_attr = target_crs->as<IfcUtil::IfcBaseEntity>()->get("Name");
 				if (coordop->declaration().is("IfcMapConversion")) {
 					
-					if (!name_attr->isNull()) {
-						std::string epsg_code = *name_attr;
+					if (!name_attr.isNull()) {
+						std::string epsg_code = name_attr;
 						crs_epsg = epsg_code;
 
 						// @todo in which unit are these?
-						double eastings = *coordop->as<IfcUtil::IfcBaseEntity>()->get("Eastings");
-						double northings = *coordop->as<IfcUtil::IfcBaseEntity>()->get("Northings");
-						double height = *coordop->as<IfcUtil::IfcBaseEntity>()->get("OrthogonalHeight");
+						double eastings = coordop->as<IfcUtil::IfcBaseEntity>()->get("Eastings");
+						double northings = coordop->as<IfcUtil::IfcBaseEntity>()->get("Northings");
+						double height = coordop->as<IfcUtil::IfcBaseEntity>()->get("OrthogonalHeight");
 						height = 0.;
 
 						eastings_northings_elevation = { { eastings, northings, height} };
 
 						auto xaxis_attr = coordop->as<IfcUtil::IfcBaseEntity>()->get("XAxisAbscissa");
 						auto yaxis_attr = coordop->as<IfcUtil::IfcBaseEntity>()->get("XAxisOrdinate");
-						if (!xaxis_attr->isNull() && !yaxis_attr->isNull()) {
-							double xaxis = *xaxis_attr;
-							double yaxis = *yaxis_attr;
+						if (!xaxis_attr.isNull() && !yaxis_attr.isNull()) {
+							double xaxis = xaxis_attr;
+							double yaxis = yaxis_attr;
 
 							crs_x_axis = { { xaxis, yaxis, 0. } };
 						}
@@ -490,9 +490,9 @@ void GltfSerializer::setFile(IfcParse::IfcFile* f) {
 			auto lat_attr = (*sites->begin())->as<IfcUtil::IfcBaseEntity>()->get("RefLatitude");
 			auto lon_attr = (*sites->begin())->as<IfcUtil::IfcBaseEntity>()->get("RefLongitude");
 
-			if (!lat_attr->isNull() && !lon_attr->isNull()) {
-				std::vector<int> lat_dms = *lat_attr;
-				std::vector<int> lon_dms = *lon_attr;
+			if (!lat_attr.isNull() && !lon_attr.isNull()) {
+				std::vector<int> lat_dms = lat_attr;
+				std::vector<int> lon_dms = lon_attr;
 
 				auto to_decimal = [](const std::vector<int>& dms) {
 					double val = dms[0] + dms[1] / 60. + dms[2] / 3600.;
@@ -524,10 +524,10 @@ void GltfSerializer::setFile(IfcParse::IfcFile* f) {
 	if (contexts && contexts->size() > 0) {
 		auto context = (*contexts->begin())->as<IfcUtil::IfcBaseEntity>();
 		auto north_attr = context->get("TrueNorth");
-		if (!north_attr->isNull()) {
-			IfcUtil::IfcBaseClass* north = *north_attr;
+		if (!north_attr.isNull()) {
+			IfcUtil::IfcBaseClass* north = north_attr;
 			if (north->declaration().is("IfcDirection")) {
-				std::vector<double> ratios = *north->as<IfcUtil::IfcBaseEntity>()->get("DirectionRatios");
+				std::vector<double> ratios = north->as<IfcUtil::IfcBaseEntity>()->get("DirectionRatios");
 				crs_x_axis = { { ratios[1], -ratios[0], 0. } };
 			}
 		}