diff --git a/src/db/db/dbHierNetworkProcessor.cc b/src/db/db/dbHierNetworkProcessor.cc
index bbb463faa..bd7dbd903 100644
--- a/src/db/db/dbHierNetworkProcessor.cc
+++ b/src/db/db/dbHierNetworkProcessor.cc
@@ -1216,11 +1216,13 @@ struct cluster_building_receiver
     db::Connectivity::global_nets_iterator ge = mp_conn->end_global_connections (p.first);
     for (db::Connectivity::global_nets_iterator g = mp_conn->begin_global_connections (p.first); g != ge; ++g) {
 
+      bool soft = (g->second != 0);
+
       typename std::map<size_t, typename std::list<cluster_value>::iterator>::iterator icg = m_global_to_clusters.find (g->first);
 
       if (icg == m_global_to_clusters.end ()) {
 
-        if (g->second != 0) {
+        if (soft) {
 
           //  soft connection to a new global cluster
           m_clusters.push_back (cluster_value ());
@@ -1240,7 +1242,7 @@ struct cluster_building_receiver
 
       } else if (ic->second != icg->second) {
 
-        if (g->second != 0) {
+        if (soft) {
 
           register_soft_connection (ic->second, icg->second, g->second);
 
diff --git a/src/db/db/dbHierNetworkProcessor.h b/src/db/db/dbHierNetworkProcessor.h
index 08ec80718..ad97c7fad 100644
--- a/src/db/db/dbHierNetworkProcessor.h
+++ b/src/db/db/dbHierNetworkProcessor.h
@@ -513,6 +513,7 @@ public:
   typedef db::box_tree<box_type, local_cluster<T>, local_cluster_box_convert<T> > tree_type;
   typedef typename tree_type::touching_iterator touching_iterator;
   typedef typename tree_type::const_iterator const_iterator;
+  typedef typename tree_type::iterator iterator;
 
   /**
    *  @brief Creates an empty collection
@@ -566,6 +567,22 @@ public:
     return m_clusters.end ();
   }
 
+  /**
+   *  @brief Gets the clusters (begin iterator)
+   */
+  iterator begin ()
+  {
+    return m_clusters.begin ();
+  }
+
+  /**
+   *  @brief Gets the clusters (end iterator)
+   */
+  iterator end ()
+  {
+    return m_clusters.end ();
+  }
+
   /**
    *  @brief Gets a value indicating whether the cluster set is empty
    */
diff --git a/src/db/db/dbNetlistExtractor.cc b/src/db/db/dbNetlistExtractor.cc
index dd4ac0c23..cfd253135 100644
--- a/src/db/db/dbNetlistExtractor.cc
+++ b/src/db/db/dbNetlistExtractor.cc
@@ -228,8 +228,8 @@ NetlistExtractor::extract_nets (const db::DeepShapeStore &dss, unsigned int layo
 
     const db::Cell &cell = mp_layout->cell (*cid);
 
-    const connected_clusters_type &clusters = mp_clusters->clusters_per_cell (*cid);
-    if (clusters.empty ()) {
+    connected_clusters_type &per_cell_clusters = mp_clusters->clusters_per_cell (*cid);
+    if (per_cell_clusters.empty ()) {
 
       bool any_good = false;
 
@@ -251,7 +251,7 @@ NetlistExtractor::extract_nets (const db::DeepShapeStore &dss, unsigned int layo
     if (dm) {
       //  This is a device abstract cell:
       //  make the terminal to cluster ID connections for the device abstract from the device cells
-      make_device_abstract_connections (dm, clusters);
+      make_device_abstract_connections (dm, per_cell_clusters);
       continue;
     }
 
@@ -284,12 +284,12 @@ NetlistExtractor::extract_nets (const db::DeepShapeStore &dss, unsigned int layo
 
     }
 
-    for (connected_clusters_type::all_iterator c = clusters.begin_all (); ! c.at_end (); ++c) {
+    for (connected_clusters_type::all_iterator c = per_cell_clusters.begin_all (); ! c.at_end (); ++c) {
 
-      const db::local_cluster<db::NetShape> &lc = clusters.cluster_by_id (*c);
-      const connected_clusters_type::connections_type &cc = clusters.connections_for_cluster (*c);
-      const std::set<size_t> &sc_up = clusters.upward_soft_connections (*c);
-      const std::set<size_t> &sc_down = clusters.downward_soft_connections (*c);
+      const db::local_cluster<db::NetShape> &lc = per_cell_clusters.cluster_by_id (*c);
+      const connected_clusters_type::connections_type &cc = per_cell_clusters.connections_for_cluster (*c);
+      const std::set<size_t> &sc_up = per_cell_clusters.upward_soft_connections (*c);
+      const std::set<size_t> &sc_down = per_cell_clusters.downward_soft_connections (*c);
       if (cc.empty () && sc_up.empty () && sc_down.empty () && lc.empty ()) {
         //  this is an entirely empty cluster so we skip it.
         //  Such clusters are left over when joining clusters.
@@ -301,14 +301,14 @@ NetlistExtractor::extract_nets (const db::DeepShapeStore &dss, unsigned int layo
       circuit->add_net (net);
 
       //  make subcircuit connections (also make the subcircuits if required) from the connections of the clusters
-      make_and_connect_subcircuits (circuit, clusters, *c, net, subcircuits, circuits, pins_per_cluster_per_cell);
+      make_and_connect_subcircuits (circuit, per_cell_clusters, *c, net, subcircuits, circuits, pins_per_cluster_per_cell);
 
       //  connect devices
-      connect_devices (circuit, clusters, *c, net);
+      connect_devices (circuit, per_cell_clusters, *c, net);
 
       //  collect labels to net names
       std::set<std::string> net_names;
-      collect_labels (clusters, *c, net_names);
+      collect_labels (per_cell_clusters, *c, net_names);
 
       //  add the global names as second priority
       if (net_names.empty ()) {
@@ -323,7 +323,7 @@ NetlistExtractor::extract_nets (const db::DeepShapeStore &dss, unsigned int layo
       //  made to satisfy the subcircuit's pin, but not to make a physical connection.
       //  Don't know whether this is a good idea, so this code is disabled for now.
 
-      if (net_names.empty () && clusters.is_dummy (*c) && net->subcircuit_pin_count () == 1) {
+      if (net_names.empty () && per_cell_clusters.is_dummy (*c) && net->subcircuit_pin_count () == 1) {
         //  in the case of a dummy connection (partially connected subcircuits) create a
         //  new name indicating the subcircuit and the subcircuit net name - this makes subcircuit
         //  net names available (the net is pseudo-root inside in the subcircuit)
@@ -337,7 +337,7 @@ NetlistExtractor::extract_nets (const db::DeepShapeStore &dss, unsigned int layo
 
       assign_net_names (net, net_names);
 
-      if (! clusters.is_root (*c)) {
+      if (! per_cell_clusters.is_root (*c)) {
         //  a non-root cluster makes a pin
         size_t pin_id = make_pin (circuit, net);
         c2p.insert (std::make_pair (*c, pin_id));
@@ -364,28 +364,73 @@ NetlistExtractor::assign_net_names (db::Net *net, const std::set<std::string> &n
   net->set_name (nn);
 }
 
+static void
+collect_soft_connected_clusters (size_t from_id, const NetlistExtractor::connected_clusters_type &clusters, std::set<size_t> &ids)
+{
+  if (ids.find (from_id) != ids.end ()) {
+    return;
+  }
+
+  ids.insert (from_id);
+
+  auto upward = clusters.upward_soft_connections (from_id);
+  for (auto i = upward.begin (); i != upward.end (); ++i) {
+    collect_soft_connected_clusters (*i, clusters, ids);
+  }
+
+  auto downward = clusters.downward_soft_connections (from_id);
+  for (auto i = downward.begin (); i != downward.end (); ++i) {
+    collect_soft_connected_clusters (*i, clusters, ids);
+  }
+}
+
 void
-NetlistExtractor::make_device_abstract_connections (db::DeviceAbstract *dm, const connected_clusters_type &clusters)
+NetlistExtractor::make_device_abstract_connections (db::DeviceAbstract *dm, connected_clusters_type &clusters)
 {
   //  make the terminal to cluster ID connections for the device abstract from the device cells
 
   if (m_terminal_annot_name_id.first) {
 
-    for (connected_clusters_type::const_iterator dc = clusters.begin (); dc != clusters.end (); ++dc) {
+    for (connected_clusters_type::iterator dc = clusters.begin (); dc != clusters.end (); ++dc) {
 
-      for (local_cluster_type::attr_iterator a = dc->begin_attr (); a != dc->end_attr (); ++a) {
+      std::set<size_t> ids;
+      collect_soft_connected_clusters (dc->id (), clusters, ids);
+
+      for (auto id = ids.begin (); id != ids.end (); ++id) {
+
+        const local_cluster_type &lc = clusters.cluster_by_id (*id);
+        bool join = false;
+
+        for (local_cluster_type::attr_iterator a = lc.begin_attr (); a != lc.end_attr (); ++a) {
+
+          if (! db::is_prop_id_attr (*a)) {
+            continue;
+          }
+
+          db::properties_id_type pi = db::prop_id_from_attr (*a);
+
+          const db::PropertiesRepository::properties_set &ps = mp_layout->properties_repository ().properties (pi);
+          for (db::PropertiesRepository::properties_set::const_iterator j = ps.begin (); j != ps.end (); ++j) {
+
+            if (j->first == m_terminal_annot_name_id.second) {
+
+              size_t terminal_id = j->second.to<size_t> ();
+              if (*id != dc->id ()) {
+                tl::warn << tl::sprintf (tl::to_string (tr ("Ignoring soft connection at device terminal %s for device %s")), dm->device_class ()->terminal_definition (terminal_id)->name (), dm->device_class ()->name ());
+                join = true;
+              }
+
+              dm->set_cluster_id_for_terminal (terminal_id, dc->id ());
+
+            }
+
+          }
 
-        if (! db::is_prop_id_attr (*a)) {
-          continue;
         }
 
-        db::properties_id_type pi = db::prop_id_from_attr (*a);
-
-        const db::PropertiesRepository::properties_set &ps = mp_layout->properties_repository ().properties (pi);
-        for (db::PropertiesRepository::properties_set::const_iterator j = ps.begin (); j != ps.end (); ++j) {
-          if (j->first == m_terminal_annot_name_id.second) {
-            dm->set_cluster_id_for_terminal (j->second.to<size_t> (), dc->id ());
-          }
+        if (join) {
+          //  copy the terminal attributes and shapes so we attach the terminal here in the device connection step
+          clusters.join_cluster_with (dc->id (), *id);
         }
 
       }
diff --git a/src/db/db/dbNetlistExtractor.h b/src/db/db/dbNetlistExtractor.h
index 18d7fed01..e06c29475 100644
--- a/src/db/db/dbNetlistExtractor.h
+++ b/src/db/db/dbNetlistExtractor.h
@@ -233,7 +233,7 @@ private:
   /**
    *  @brief Makes the terminal to cluster ID connections of the device abstract
    */
-  void make_device_abstract_connections (db::DeviceAbstract *dm, const connected_clusters_type &clusters);
+  void make_device_abstract_connections (db::DeviceAbstract *dm, connected_clusters_type &clusters);
 
 };
 
diff --git a/src/lvs/unit_tests/lvsSimpleTests.cc b/src/lvs/unit_tests/lvsSimpleTests.cc
index ac141d640..1f06fefcf 100644
--- a/src/lvs/unit_tests/lvsSimpleTests.cc
+++ b/src/lvs/unit_tests/lvsSimpleTests.cc
@@ -305,6 +305,8 @@ TEST(40_DeviceExtractorErrors)
 TEST(50_BasicSoftConnection)
 {
   run_test (_this, "soft_connect1", "soft_connect1.gds", true, false /*no LVS*/);
+  //  issue #1691
+  run_test (_this, "soft_connect1a", "soft_connect1.gds", true, false /*no LVS*/);
 }
 
 //  No errors
diff --git a/testdata/lvs/soft_connect1a.cir b/testdata/lvs/soft_connect1a.cir
new file mode 100644
index 000000000..61ac75956
--- /dev/null
+++ b/testdata/lvs/soft_connect1a.cir
@@ -0,0 +1,13 @@
+* Extracted by KLayout
+
+.SUBCKT TOP A Q VDD SUBSTRATE|VSS
+X$1 SUBSTRATE|VSS VDD VDD \$1 Q SUBSTRATE|VSS INV
+X$2 SUBSTRATE|VSS VDD VDD A \$1 SUBSTRATE|VSS INV
+.ENDS TOP
+
+.SUBCKT INV \$1 \$2 \$3 \$4 \$5 SUBSTRATE
+M$1 \$2 \$4 \$5 \$3 PMOS L=0.25U W=0.95U AS=0.73625P AD=0.73625P PS=3.45U
++ PD=3.45U
+M$2 \$1 \$4 \$5 SUBSTRATE NMOS L=0.25U W=0.95U AS=0.73625P AD=0.73625P PS=3.45U
++ PD=3.45U
+.ENDS INV
diff --git a/testdata/lvs/soft_connect1a.l2n b/testdata/lvs/soft_connect1a.l2n
new file mode 100644
index 000000000..c65a7d112
--- /dev/null
+++ b/testdata/lvs/soft_connect1a.l2n
@@ -0,0 +1,218 @@
+#%l2n-klayout
+W(TOP)
+U(0.001)
+L(l3 '1/0')
+L(l4 '3/0')
+L(l15 '3/1')
+L(l8 '4/0')
+L(l11 '5/0')
+L(l12 '6/0')
+L(l16 '6/1')
+L(l13 '7/0')
+L(l14 '8/0')
+L(l17 '8/1')
+L(l7)
+L(l10)
+L(l2)
+L(l9)
+L(l6)
+C(l3 l3 l10)
+C(l4 l4 l15 l11)
+C(l15 l4 l15)
+C(l8 l8 l12 l10 l2 l9 l6)
+CS(l8 l10 l2 l9 l6)
+C(l11 l4 l11 l12)
+CS(l11 l4)
+C(l12 l8 l11 l12 l16 l13)
+C(l16 l12 l16)
+C(l13 l12 l13 l14)
+C(l14 l13 l14 l17)
+C(l17 l14 l17)
+C(l7 l7)
+C(l10 l3 l8 l10)
+CS(l10 l3)
+C(l2 l8 l2)
+C(l9 l8 l9)
+C(l6 l8 l6)
+G(l7 SUBSTRATE)
+GS(l7 SUBSTRATE)
+G(l9 SUBSTRATE)
+GS(l9 SUBSTRATE)
+H(W B('Net with incomplete wiring (soft-connected partial nets)') C(TOP) X('soft-connection-check'))
+H(B('\tPartial net #1: TOP - VDD') C(TOP) Q('(0.6,3.95;0.6,4.85;4.5,4.85;4.5,3.95)'))
+H(B('\tPartial net #2: TOP - $I4') C(TOP) Q('(5.1,3.95;5.1,4.85;9,4.85;9,3.95)'))
+H(W B('Net with incomplete wiring (soft-connected partial nets)') C(TOP) X('soft-connection-check'))
+H(B('\tPartial net #1: TOP - VSS') C(TOP) Q('(0.6,1.15;0.6,2.05;4.5,2.05;4.5,1.15)'))
+H(B('\tPartial net #2: TOP - $I1') C(TOP) Q('(5.1,1.15;5.1,2.05;9,2.05;9,1.15)'))
+K(PMOS MOS4)
+K(NMOS MOS4)
+D(D$PMOS PMOS
+ T(S
+  R(l2 (-900 -475) (775 950))
+ )
+ T(G
+  R(l4 (-125 -475) (250 950))
+ )
+ T(D
+  R(l2 (125 -475) (775 950))
+ )
+ T(B
+  R(l3 (-125 -475) (250 950))
+ )
+)
+D(D$NMOS NMOS
+ T(S
+  R(l6 (-900 -475) (775 950))
+ )
+ T(G
+  R(l4 (-125 -475) (250 950))
+ )
+ T(D
+  R(l6 (125 -475) (775 950))
+ )
+ T(B
+  R(l7 (-125 -475) (250 950))
+ )
+)
+X(INV
+ R((-1500 -800) (3000 4600))
+ N(1
+  R(l8 (290 -310) (220 220))
+  R(l8 (-220 180) (220 220))
+  R(l12 (-290 -690) (360 760))
+  R(l13 (-305 -705) (250 250))
+  R(l13 (-250 150) (250 250))
+  R(l14 (-2025 -775) (3000 900))
+  R(l6 (-1375 -925) (775 950))
+ )
+ N(2
+  R(l8 (290 2490) (220 220))
+  R(l8 (-220 180) (220 220))
+  R(l12 (-290 -690) (360 760))
+  R(l13 (-305 -705) (250 250))
+  R(l13 (-250 150) (250 250))
+  R(l14 (-2025 -775) (3000 900))
+  R(l2 (-1375 -925) (775 950))
+ )
+ N(3
+  R(l3 (-1500 1800) (3000 2000))
+ )
+ N(4
+  R(l4 (-125 -250) (250 2500))
+  R(l4 (-250 -3050) (250 1600))
+  R(l4 (-250 1200) (250 1600))
+ )
+ N(5
+  R(l8 (-510 -310) (220 220))
+  R(l8 (-220 180) (220 220))
+  R(l8 (-220 2180) (220 220))
+  R(l8 (-220 180) (220 220))
+  R(l12 (-290 -3530) (360 2840))
+  R(l12 (-360 -2800) (360 760))
+  R(l12 (-360 2040) (360 760))
+  R(l2 (-680 -855) (775 950))
+  R(l6 (-775 -3750) (775 950))
+ )
+ N(6 I(SUBSTRATE))
+ P(1)
+ P(2)
+ P(3)
+ P(4)
+ P(5)
+ P(6 I(SUBSTRATE))
+ D(1 D$PMOS
+  Y(0 2800)
+  E(L 0.25)
+  E(W 0.95)
+  E(AS 0.73625)
+  E(AD 0.73625)
+  E(PS 3.45)
+  E(PD 3.45)
+  T(S 5)
+  T(G 4)
+  T(D 2)
+  T(B 3)
+ )
+ D(2 D$NMOS
+  Y(0 0)
+  E(L 0.25)
+  E(W 0.95)
+  E(AS 0.73625)
+  E(AD 0.73625)
+  E(PS 3.45)
+  E(PD 3.45)
+  T(S 5)
+  T(G 4)
+  T(D 1)
+  T(B 6)
+ )
+)
+X(TOP
+ R((600 800) (8880 4600))
+ N(1
+  R(l4 (2920 2600) (2880 400))
+  R(l11 (-300 -300) (200 200))
+  R(l12 (-300 -300) (690 400))
+ )
+ N(2 I(A)
+  R(l4 (6600 2600) (2880 400))
+  R(l15 (-2380 -200) (0 0))
+ )
+ N(3 I(Q)
+  R(l12 (1810 2600) (690 400))
+  R(l16 (-400 -200) (0 0))
+ )
+ N(4 I(VDD)
+  R(l3 (4000 3400) (1600 2000))
+  R(l3 (-5000 -2000) (1000 2000))
+  R(l3 (6400 -2000) (1000 2000))
+  R(l8 (-8000 -900) (200 200))
+  R(l8 (-200 -600) (200 200))
+  R(l8 (7200 200) (200 200))
+  R(l8 (-200 -600) (200 200))
+  R(l12 (-7900 -350) (800 900))
+  R(l12 (6600 -900) (800 900))
+  R(l13 (-7900 -350) (200 200))
+  R(l13 (-200 -600) (200 200))
+  R(l13 (7200 200) (200 200))
+  R(l13 (-200 -600) (200 200))
+  R(l14 (-8000 -350) (1000 900))
+  R(l14 (6400 -900) (1000 900))
+  R(l17 (-4800 -450) (0 0))
+ )
+ N(5 I('SUBSTRATE,VSS')
+  R(l8 (1000 1700) (200 200))
+  R(l8 (-200 -600) (200 200))
+  R(l8 (7200 200) (200 200))
+  R(l8 (-200 -600) (200 200))
+  R(l12 (-7900 -350) (800 900))
+  R(l12 (6600 -900) (800 900))
+  R(l13 (-7900 -350) (200 200))
+  R(l13 (-200 -600) (200 200))
+  R(l13 (7200 200) (200 200))
+  R(l13 (-200 -600) (200 200))
+  R(l14 (-8000 -350) (1000 900))
+  R(l14 (6400 -900) (1000 900))
+  R(l17 (-4800 -550) (0 0))
+ )
+ P(2 I(A))
+ P(3 I(Q))
+ P(4 I(VDD))
+ P(5 I('SUBSTRATE,VSS'))
+ X(1 INV Y(3000 1600)
+  P(0 5)
+  P(1 4)
+  P(2 4)
+  P(3 1)
+  P(4 3)
+  P(5 5)
+ )
+ X(2 INV Y(6600 1600)
+  P(0 5)
+  P(1 4)
+  P(2 4)
+  P(3 2)
+  P(4 1)
+  P(5 5)
+ )
+)
diff --git a/testdata/lvs/soft_connect1a.lvs b/testdata/lvs/soft_connect1a.lvs
new file mode 100644
index 000000000..4063000dc
--- /dev/null
+++ b/testdata/lvs/soft_connect1a.lvs
@@ -0,0 +1,92 @@
+
+$lvs_test_source && source($lvs_test_source)
+
+if $lvs_test_target_l2n
+  report_netlist($lvs_test_target_l2n)
+else
+  report_netlist
+end
+
+writer = write_spice(true, false)
+$lvs_test_target_cir && target_netlist($lvs_test_target_cir, writer, "Extracted by KLayout")
+
+deep
+
+# Drawing layers
+
+nwell       = input(1, 0)
+active      = input(2, 0)
+nplus       = input(2, 1)
+pplus       = input(2, 2)
+poly        = input(3, 0)
+poly_lbl    = input(3, 1)
+diff_cont   = input(4, 0)
+poly_cont   = input(5, 0)
+metal1      = input(6, 0)
+metal1_lbl  = input(6, 1)
+via1        = input(7, 0)
+metal2      = input(8, 0)
+metal2_lbl  = input(8, 1)
+
+# Bulk layer for terminal provisioning
+
+bulk        = polygon_layer
+
+psd = nil
+nsd = nil
+
+# Computed layers
+
+active_in_nwell       = active & nwell
+pactive               = active_in_nwell & pplus
+ntie                  = active_in_nwell & nplus
+pgate                 = pactive & poly
+psd                   = pactive - pgate
+
+active_outside_nwell  = active - nwell
+nactive               = active_outside_nwell & nplus
+ptie                  = active_outside_nwell & pplus
+ngate                 = nactive & poly
+nsd                   = nactive - ngate
+
+# Device extraction
+
+# PMOS transistor device extraction
+extract_devices(mos4("PMOS"), { "SD" => psd, "G" => pgate, "W" => nwell,
+                                "tS" => psd, "tD" => psd, "tG" => poly })
+
+# NMOS transistor device extraction
+extract_devices(mos4("NMOS"), { "SD" => nsd, "G" => ngate, "W" => bulk,
+                                "tS" => nsd, "tD" => nsd, "tG" => poly })
+
+# Define connectivity for netlist extraction
+
+# Inter-layer
+
+soft_connect(diff_cont, psd)
+soft_connect(diff_cont, nsd)
+soft_connect(diff_cont, ptie)
+soft_connect(diff_cont, ntie)
+soft_connect(ntie, nwell)
+soft_connect(poly_cont, poly)
+
+connect(diff_cont, metal1)
+connect(poly_cont, metal1)
+connect(metal1, via1)
+connect(via1, metal2)
+
+# attach labels
+connect(poly, poly_lbl)
+connect(metal1, metal1_lbl)
+connect(metal2, metal2_lbl)
+
+# Global
+soft_connect_global(bulk, "SUBSTRATE")
+soft_connect_global(ptie, "SUBSTRATE")
+
+# Netlist section (NOTE: we only check log here)
+netlist
+
+netlist.simplify
+
+