diff --git a/src/db/db/dbHierNetworkProcessor.cc b/src/db/db/dbHierNetworkProcessor.cc
index f3db932aa..b424ed4cd 100644
--- a/src/db/db/dbHierNetworkProcessor.cc
+++ b/src/db/db/dbHierNetworkProcessor.cc
@@ -740,7 +740,6 @@ private:
   hier_clusters<T> *mp_tree;
   const cell_clusters_box_converter<T> *mp_cbc;
   const db::Connectivity *mp_conn;
-  connector_map m_connectors;
   std::map<id_type, std::set<id_type> *> m_cm2join_map;
   std::list<std::set<id_type> > m_cm2join_sets;
 
@@ -846,31 +845,29 @@ private:
           ClusterInstance k1 = make_path (i->id (), p1);
           ClusterInstance k2 = make_path (j->id (), p2);
 
-          typename connector_map::iterator x1 = m_connectors.find (k1);
-          typename connector_map::iterator x2 = m_connectors.find (k2);
+          id_type x1 = mp_cell_clusters->find_cluster_with_connection (k1);
+          id_type x2 = mp_cell_clusters->find_cluster_with_connection (k2);
 
-          if (x1 == m_connectors.end ()) {
+          if (x1 == 0) {
 
-            if (x2 == m_connectors.end ()) {
+            if (x2 == 0) {
 
               id_type connector = mp_cell_clusters->insert_dummy ();
-              m_connectors [k1] = connector;
               mp_cell_clusters->add_connection (connector, k1);
               mp_cell_clusters->add_connection (connector, k2);
 
             } else {
-              mp_cell_clusters->add_connection (x2->second, k1);
+              mp_cell_clusters->add_connection (x2, k1);
             }
 
-          } else if (x2 == m_connectors.end ()) {
+          } else if (x2 == 0) {
 
-            mp_cell_clusters->add_connection (x1->second, k2);
+            mp_cell_clusters->add_connection (x1, k2);
 
-          } else if (x1->second != x2->second) {
+          } else if (x1 != x2) {
 
-            mp_cell_clusters->join_cluster_with (x1->second, x2->second);
-            mp_cell_clusters->remove_cluster (x2->second);
-            x2->second = x1->second;
+            mp_cell_clusters->join_cluster_with (x1, x2);
+            mp_cell_clusters->remove_cluster (x2);
 
           }
 
diff --git a/src/db/db/dbHierNetworkProcessor.h b/src/db/db/dbHierNetworkProcessor.h
index 69918db97..1c57b9513 100644
--- a/src/db/db/dbHierNetworkProcessor.h
+++ b/src/db/db/dbHierNetworkProcessor.h
@@ -342,6 +342,12 @@ public:
     //  .. nothing yet ..
   }
 
+  ClusterInstance ()
+    : m_id (0), m_inst ()
+  {
+    //  .. nothing yet ..
+  }
+
   /**
    *  @brief Gets the cluster ID
    */
diff --git a/src/db/unit_tests/dbHierNetworkProcessorTests.cc b/src/db/unit_tests/dbHierNetworkProcessorTests.cc
index 6ed5f38ad..fab9c5d49 100644
--- a/src/db/unit_tests/dbHierNetworkProcessorTests.cc
+++ b/src/db/unit_tests/dbHierNetworkProcessorTests.cc
@@ -585,3 +585,18 @@ TEST(48_HierClusters)
 {
   run_hc_test (_this, "hc_test_l8.gds", "hc_test_au8.gds");
 }
+
+TEST(49_HierClusters)
+{
+  run_hc_test (_this, "hc_test_l9.gds", "hc_test_au9.gds");
+}
+
+TEST(50_HierClusters)
+{
+  run_hc_test (_this, "hc_test_l10.gds", "hc_test_au10.gds");
+}
+
+TEST(51_HierClusters)
+{
+  run_hc_test (_this, "hc_test_l11.gds", "hc_test_au11.gds");
+}
diff --git a/testdata/algo/hc_test_au10.gds b/testdata/algo/hc_test_au10.gds
new file mode 100644
index 000000000..d7c92fb93
Binary files /dev/null and b/testdata/algo/hc_test_au10.gds differ
diff --git a/testdata/algo/hc_test_au11.gds b/testdata/algo/hc_test_au11.gds
new file mode 100644
index 000000000..9552f7549
Binary files /dev/null and b/testdata/algo/hc_test_au11.gds differ
diff --git a/testdata/algo/hc_test_au9.gds b/testdata/algo/hc_test_au9.gds
new file mode 100644
index 000000000..16ac993e5
Binary files /dev/null and b/testdata/algo/hc_test_au9.gds differ
diff --git a/testdata/algo/hc_test_l10.gds b/testdata/algo/hc_test_l10.gds
new file mode 100644
index 000000000..b4906fc32
Binary files /dev/null and b/testdata/algo/hc_test_l10.gds differ
diff --git a/testdata/algo/hc_test_l11.gds b/testdata/algo/hc_test_l11.gds
new file mode 100644
index 000000000..21037004c
Binary files /dev/null and b/testdata/algo/hc_test_l11.gds differ
diff --git a/testdata/algo/hc_test_l9.gds b/testdata/algo/hc_test_l9.gds
new file mode 100644
index 000000000..ebbf2798e
Binary files /dev/null and b/testdata/algo/hc_test_l9.gds differ