diff --git a/Code/GraphMol/CMakeLists.txt b/Code/GraphMol/CMakeLists.txt
index ca207eb6b..0c70732a6 100644
--- a/Code/GraphMol/CMakeLists.txt
+++ b/Code/GraphMol/CMakeLists.txt
@@ -93,6 +93,6 @@ rdkit_test(graphmoltestPickler testPickler.cpp
 rdkit_test(graphmolIterTest itertest.cpp LINK_LIBRARIES SmilesParse GraphMol RDGeometryLib RDGeneral)
 
 rdkit_test(hanoiTest hanoitest.cpp LINK_LIBRARIES SmilesParse_static FileParsers_static GraphMol_static
-RDGeometryLib_static RDGeneral_static )
+RDGeometryLib_static RDGeneral_static ${RDKit_THREAD_LIBS} )
 
 
diff --git a/Code/GraphMol/hanoitest.cpp b/Code/GraphMol/hanoitest.cpp
index 212c320df..35f98e516 100644
--- a/Code/GraphMol/hanoitest.cpp
+++ b/Code/GraphMol/hanoitest.cpp
@@ -812,6 +812,7 @@ void test7(){
     "C[C@H]1C[C@H](C1)N1CCN(C)CC1",
     "CN1CCN(CC1)[C@H]1C[C@H](C1)c1ncc2c(N)nccn12",
     "CN1CCN(CC1)[C@H]1C[C@H](C1)c1nc(-c2ccc3ccc(nc3c2)-c2ccccc2)c2c(N)nccn12",
+    "*12*3*1*3*4*5*4*52",
     "EOS"
   };
   unsigned int i=0;
diff --git a/Code/GraphMol/roger_canon.h b/Code/GraphMol/roger_canon.h
index a9c282c8b..37d55169a 100644
--- a/Code/GraphMol/roger_canon.h
+++ b/Code/GraphMol/roger_canon.h
@@ -291,8 +291,12 @@ namespace RDKit {
           return 1;
         
         // ring membership
-        ivi=dp_mol->getRingInfo()->numAtomRings(dp_atoms[i].atom->getIdx())!=0;
-        ivj=dp_mol->getRingInfo()->numAtomRings(dp_atoms[j].atom->getIdx())!=0;
+        // initial passes at this were just checking "isInRing" to allow
+        // a possible future more efficient check. These break on this
+        // lovely double-diamond pathological case:
+        //   *12*3*1*3*4*5*4*52
+        ivi=dp_mol->getRingInfo()->numAtomRings(dp_atoms[i].atom->getIdx());
+        ivj=dp_mol->getRingInfo()->numAtomRings(dp_atoms[j].atom->getIdx());
         if(ivi<ivj)
           return -1;
         else if(ivi>ivj)