diff --git a/src/ifcgeomserver/IfcGeomServer.cpp b/src/ifcgeomserver/IfcGeomServer.cpp
index b51166bcbe..15cd7e546b 100644
--- a/src/ifcgeomserver/IfcGeomServer.cpp
+++ b/src/ifcgeomserver/IfcGeomServer.cpp
@@ -353,7 +353,7 @@ protected:
 			// We remove the blanks here from the material array. I.e. materials without a diffuse color
 			std::vector<boost::optional<std::array<float, 4> > > diffuse_color_array;
 			for (auto it = geom->geometry().materials().begin(); it != geom->geometry().materials().end(); ++it) {
-				const auto& mat = *it;
+				const auto& mat = **it;
 				if (mat.diffuse) {
 					const auto& color = mat.diffuse.ccomponents();
 					diffuse_color_array.push_back(std::array<float, 4>{