diff --git a/FileIO/GmshIO/GMSHPolygonTree.cpp b/FileIO/GmshIO/GMSHPolygonTree.cpp
index 9f5e1b218b1bbac2f217e3c0e4bf0c1c2e524983..95592b68b8527b7d605fbe6de4c3a3826c822379 100644
--- a/FileIO/GmshIO/GMSHPolygonTree.cpp
+++ b/FileIO/GmshIO/GMSHPolygonTree.cpp
@@ -42,6 +42,8 @@ GMSHPolygonTree::~GMSHPolygonTree()
 		for (auto * polyline : _plys)
 			delete polyline;
 	}
+	// member of GeoLib::SimplePolygonTree, but the ownership is not transmitted
+	delete _node_polygon;
 }
 
 bool GMSHPolygonTree::insertStation(GeoLib::Point const* station)