diff --git a/sidechain/src/rotamer_constructor.cc b/sidechain/src/rotamer_constructor.cc
index 354e2c4b22b199c632d7f8ffa9536476c98ea320..48c5189a85750eddfd820e5a35e4bdda645383ce 100644
--- a/sidechain/src/rotamer_constructor.cc
+++ b/sidechain/src/rotamer_constructor.cc
@@ -914,7 +914,7 @@ FrameResiduePtr RotamerConstructor::ConstructBackboneFrameResidue() {
 
   // set hydrogens (also enter if its an n_ter because proline would have no 
   // hydrogen)
-  if(info.has_hydrogens || n_ter_){
+  if((info.has_hydrogens || n_ter_) && mode_ != HEAVY_ATOM_MODE) {
     if(mode_ == FULL_ATOMIC_MODE) {
       promod3::loop::ConstructHydrogens(*pos_buffer_, id_, *hydrogen_buffer_,
                                         mode_ == POLAR_HYDROGEN_MODE,