diff --git a/libsrc/meshing/basegeom.cpp b/libsrc/meshing/basegeom.cpp
index f5d67144..cb5b8407 100644
--- a/libsrc/meshing/basegeom.cpp
+++ b/libsrc/meshing/basegeom.cpp
@@ -976,6 +976,12 @@ namespace netgen
           }
 
     xbool do_invert = maybe;
+    if(dst.identifications[0].type == Identifications::PERIODIC)
+      {
+        auto other = static_cast<GeometryFace*>(dst.primary);
+        if(dst.domin != other->domout && dst.domout != other->domin)
+          do_invert = true;
+      }
 
     // now insert mapped surface elements
     for(auto sei : mesh.SurfaceElements().Range())