diff --git a/src/mmg3d/swapgen_3d.c b/src/mmg3d/swapgen_3d.c
index cac3926df..e512721b9 100644
--- a/src/mmg3d/swapgen_3d.c
+++ b/src/mmg3d/swapgen_3d.c
@@ -147,7 +147,7 @@ MMG5_int MMG5_chkswpgen(MMG5_pMesh mesh,MMG5_pSol met,MMG5_int start,int ia,
     calnew = 1.0;
     ier = 1;
 
-    if ( mesh->info.fem ) {
+    if ( mesh->info.fem == typchk ) {
       /* Do not create internal edges between boundary points */
       p0 = &mesh->point[np];
       if ( p0->tag & MG_BDY ) {
@@ -207,7 +207,8 @@ MMG5_int MMG5_chkswpgen(MMG5_pMesh mesh,MMG5_pSol met,MMG5_int start,int ia,
       }
 
       /* Prevent from creating a tetra with 4 bdy vertices */
-      if ( mesh->point[np].tag & MG_BDY ) {
+      /* when the mesh is in FEM mode */
+      if ( mesh->info.fem == typchk && (mesh->point[np].tag & MG_BDY) ) {
         if ( ( mesh->point[pt->v[MMG5_ifar[i][0]]].tag & MG_BDY ) &&
              ( mesh->point[pt->v[MMG5_ifar[i][1]]].tag & MG_BDY ) ) {
           if ( ( mesh->point[pt->v[MMG5_iare[i][0]]].tag & MG_BDY ) ||