diff --git a/src/ifcgeom/mapping/IfcFixedReferenceSweptAreaSolid.cpp b/src/ifcgeom/mapping/IfcFixedReferenceSweptAreaSolid.cpp
index 9e4fbcb441..6f349d7675 100644
--- a/src/ifcgeom/mapping/IfcFixedReferenceSweptAreaSolid.cpp
+++ b/src/ifcgeom/mapping/IfcFixedReferenceSweptAreaSolid.cpp
@@ -67,12 +67,10 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcFixedReferenceSweptAreaSolid
 		for (size_t i = 0; i <= num_steps; ++i) {
 			auto m4 = pwf->evaluate(start + curve_length / num_steps * i);
 			
-			/*
 			std::stringstream ss;
 			ss << m4;
 			auto s = ss.str();
 			std::wcout << s.c_str() << std::endl;
-			*/
 
 			Eigen::Matrix4d m4b = Eigen::Matrix4d::Identity();
 			bool is_directrix_derived = false;
@@ -85,8 +83,8 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcFixedReferenceSweptAreaSolid
 			auto pos = m4.col(3).head<3>();
 
 			if (is_directrix_derived) {
-				m4b.col(0).head<3>() = m4.col(2).head<3>().cross(m4.col(0).head<3>());
-				m4b.col(1).head<3>() = m4.col(2).head<3>();
+				m4b.col(0).head<3>() = m4.col(1).head<3>();
+				m4b.col(1).head<3>() = m4.col(0).head<3>().cross(m4.col(1).head<3>());
 				m4b.col(2).head<3>() = m4.col(0).head<3>();
 				m4b.col(3).head<3>() = pos;
 			} else {
diff --git a/src/ifcparse/IfcAlignmentHelper.cpp b/src/ifcparse/IfcAlignmentHelper.cpp
index 9913507f5a..0e73b1cadf 100644
--- a/src/ifcparse/IfcAlignmentHelper.cpp
+++ b/src/ifcparse/IfcAlignmentHelper.cpp
@@ -76,10 +76,12 @@ std::tuple<typename aggregate_of<Ifc4x3_add2::IfcObjectDefinition>::ptr, typenam
     typename aggregate_of<Ifc4x3_add2::IfcSegment>::ptr horizontal_curve_segments(include_geometry ? new aggregate_of<Ifc4x3_add2::IfcSegment>() : nullptr);             // geometry
 
     auto point_iter = points.begin();
-    auto [xBT, yBT] = *point_iter;
+    double xBT, yBT, xPI, yPI;
+
+    boost::tie(xBT, yBT) = *point_iter;
 
     point_iter++;
-    auto [xPI, yPI] = *point_iter;
+    boost::tie(xPI, yPI) = *point_iter;
 
     double xFT, yFT;
     for (auto radius : radii) {
@@ -227,10 +229,12 @@ std::tuple<typename aggregate_of<Ifc4x3_add2::IfcObjectDefinition>::ptr, typenam
     typename aggregate_of<Ifc4x3_add2::IfcSegment>::ptr vertical_curve_segments(new aggregate_of<Ifc4x3_add2::IfcSegment>());             // geometry
 
     auto point_iter = vpoints.begin();
-    auto [xPBG, yPBG] = *point_iter;
+    double xPBG, yPBG, xPVI, yPVI;
+
+    boost::tie(xPBG, yPBG) = *point_iter;
 
     point_iter++;
-    auto [xPVI, yPVI] = *point_iter;
+    boost::tie(xPVI, yPVI) = *point_iter;
 
     double xPFG, yPFG;
     for (auto length : vclengths) {