diff --git a/Mesh/meshGRegionBoundaryRecovery.cpp b/Mesh/meshGRegionBoundaryRecovery.cpp
index 2e4719a6bb69142327a274b92d864ab60a5d1022..b13a248845d9bfce0be5307c32582d2f6e603520 100644
--- a/Mesh/meshGRegionBoundaryRecovery.cpp
+++ b/Mesh/meshGRegionBoundaryRecovery.cpp
@@ -110,7 +110,7 @@ bool tetgenmesh::reconstructmesh(void *p)
 
   // Get the set of vertices from GRegion.
   {
-    std::set<MVertex*> all;
+    std::set<MVertex*, MVertexLessThanNum> all;
     std::list<GFace*> f = _gr->faces();
     for (std::list<GFace*>::iterator it = f.begin(); it != f.end(); ++it) {
       GFace *gf = *it;