diff --git a/Code/GraphMol/RGroupDecomposition/RGroupDecomp.cpp b/Code/GraphMol/RGroupDecomposition/RGroupDecomp.cpp
index b3acfd362..1df6c359d 100644
--- a/Code/GraphMol/RGroupDecomposition/RGroupDecomp.cpp
+++ b/Code/GraphMol/RGroupDecomposition/RGroupDecomp.cpp
@@ -38,6 +38,7 @@
 #include <GraphMol/ChemTransforms/ChemTransforms.h>
 #include <GraphMol/FMCS/FMCS.h>
 #include <boost/scoped_ptr.hpp>
+#include <boost/dynamic_bitset.hpp>
 #include <set>
 #include <utility>
 #include <vector>
@@ -170,9 +171,6 @@ bool RGroupDecompositionParameters::prepareCore(RWMol &core,
   MolOps::AdjustQueryParameters adjustParams;
   adjustParams.makeDummiesQueries = true;
   adjustParams.adjustDegree = false;
-  adjustParams.adjustHeavyDegree = onlyMatchAtRGroups;
-  // if (onlyMatchAtRGroups)
-  //   adjustParams.adjustDegreeFlags |= MolOps::ADJUST_IGNOREHS;
   adjustQueryProperties(core, &adjustParams);
 
   for (auto &it : atomToLabel)
@@ -577,13 +575,14 @@ struct RGroupDecompData {
       auto atm = atoms.find(userLabel);
       if (atm == atoms.end()) continue;  // label not used in the rgroup
       Atom *atom = atm->second;
-      mappings[userLabel] = ++count;
-
+      mappings[userLabel] = userLabel;
+      if(count < userLabel)
+        count = userLabel;
       if (atom->getAtomicNum() == 0) {  // add to existing dummy/rlabel
-        setRlabel(atom, count);
+        setRlabel(atom, userLabel);
       } else {  // adds new rlabel
         auto *newAt = new Atom(0);
-        setRlabel(newAt, count);
+        setRlabel(newAt, userLabel);
         atomsToAdd.push_back(std::make_pair(atom, newAt));
       }
     }
@@ -639,8 +638,6 @@ struct RGroupDecompData {
     }
 
     mol.setProp(done, true);
-    // std::cerr << "==> relabelling: " << mol.getProp<int>("idx") << " <++idx"
-    // << std::endl;
 
     std::vector<std::pair<Atom *, Atom *>> atomsToAdd;  // adds -R if necessary
 
@@ -823,6 +820,52 @@ int RGroupDecomposition::add(const ROMol &inmol) {
                      useChirality);
     }
 
+    if (data->params.onlyMatchAtRGroups) {
+      // First find all the core atoms that have user
+      //  label and but their indices into core_atoms_with_user_labels
+      std::set<int> core_atoms_with_user_labels;
+
+      for(auto atom : coreIt->second.atoms()) {
+        if(atom->hasProp(RLABEL)) {
+          core_atoms_with_user_labels.insert(atom->getIdx());
+        }
+      }
+
+      std::vector<MatchVectType> tmatches_filtered;
+      for(auto &mv : tmatches) {
+        bool passes_filter = true;
+        boost::dynamic_bitset<> target_match_indices(mol.getNumAtoms());
+        for(auto &match : mv) {
+          target_match_indices[match.second] = 1;
+        }
+        
+        for(auto &match : mv) {
+          const Atom* atm= mol.getAtomWithIdx(match.second);
+          // is this a labelled rgroup or not?
+          if(core_atoms_with_user_labels.find(match.first) ==
+             core_atoms_with_user_labels.end()) {
+
+            // nope... if any neighbor is not part of the substructure
+            //  make sure we are a hydrogen, otherwise, skip the match
+            for (const auto &nbri : boost::make_iterator_range(mol.getAtomNeighbors(atm))) {
+              const auto &nbr = mol[nbri];
+              if(nbr->getAtomicNum() != 1 && !target_match_indices[nbr->getIdx()]) {
+                passes_filter=false;
+                break;
+              }
+            }
+          }
+          if(!passes_filter)
+            break;
+        }
+
+        if (passes_filter) {
+          tmatches_filtered.push_back( mv );
+        } 
+      }
+      tmatches = tmatches_filtered;
+    }
+    
     if (!tmatches.size()) {
       continue;
     } else {
diff --git a/Code/GraphMol/RGroupDecomposition/Wrap/test_rgroups.py b/Code/GraphMol/RGroupDecomposition/Wrap/test_rgroups.py
index 4003ab978..135b345fa 100644
--- a/Code/GraphMol/RGroupDecomposition/Wrap/test_rgroups.py
+++ b/Code/GraphMol/RGroupDecomposition/Wrap/test_rgroups.py
@@ -1,4 +1,4 @@
-#  Copyright (c) 2017, Novartis Institutes for BioMedical Research Inc.
+#  Copyright (c) 2018, Novartis Institutes for BioMedical Research Inc.
 #  All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -41,7 +41,7 @@ from rdkit.Chem.rdRGroupDecomposition import RGroupDecompose, RGroupDecompositio
 from collections import OrderedDict
 
 class TestCase(unittest.TestCase) :
-    def atest_multicores(self):
+    def test_multicores(self):
         cores_smi_easy = OrderedDict()
         cores_smi_hard = OrderedDict()
 
@@ -162,9 +162,49 @@ C1CCO[C@@](S)(P)1
                 Chem.MolFromSmiles("CC")]
 
         res, unmatched = RGroupDecompose(cores, mols)
-        self.assertEquals(len(res), 1)
-        self.assertEquals(unmatched, [0,1,2,4])
-        
+        self.assertEqual(len(res), 1)
+        self.assertEqual(unmatched, [0,1,2,4])
+
+    def test_userlabels(self):
+        smis = ["C(Cl)N(N)O(O)"]
+        mols = [Chem.MolFromSmiles(smi) for smi in smis]
+        smarts = 'C([*:1])N([*:5])O([*:6])'
+        core = Chem.MolFromSmarts(smarts)
+        rg = RGroupDecomposition(core)
+        for m in mols:
+            rg.Add(m)
+        rg.Process()
+        self.assertEqual(rg.GetRGroupsAsColumns(asSmiles=True),
+                         {'Core': ['C(N(O[*:6])[*:5])[*:1]'],
+                          'R1': ['Cl[*:1]'],
+                          'R5': ['[H]N([H])[*:5]'],
+                          'R6': ['[H]O[*:6]']})
+
+        smarts = 'C([*:4])N([*:5])O([*:6])'
+
+        core = Chem.MolFromSmarts(smarts)
+        rg = RGroupDecomposition(core)
+        for m in mols:
+            rg.Add(m)
+        rg.Process()
+        self.assertEqual(rg.GetRGroupsAsColumns(asSmiles=True),
+                         {'Core': ['C(N(O[*:6])[*:5])[*:4]'],
+                          'R4': ['Cl[*:4]'],
+                          'R5': ['[H]N([H])[*:5]'],
+                          'R6': ['[H]O[*:6]']})
+
+    def test_match_only_at_rgroups(self):
+        smiles = ['c1ccccc1']#, 'c1(Cl)ccccc1', 'c1(Cl)cc(Br)ccc1']
+        mols = [Chem.MolFromSmiles(smi) for smi in smiles]
+
+        core1 = Chem.MolFromSmiles("c1([*:5])cc([*:6])ccc1")
+        params = RGroupDecompositionParameters()
+        params.onlyMatchAtRGroups=True
+        rg = RGroupDecomposition(core1, params)
+        for smi,m in zip(smiles,mols):
+            self.assertTrue(rg.Add(m)!=-1, smi)
+
+
 
 if __name__ == '__main__':
   unittest.main()