diff --git a/src/db/db/dbLayoutToNetlistReader.cc b/src/db/db/dbLayoutToNetlistReader.cc
index 2ef9ed8fd..d809398d1 100644
--- a/src/db/db/dbLayoutToNetlistReader.cc
+++ b/src/db/db/dbLayoutToNetlistReader.cc
@@ -632,6 +632,9 @@ LayoutToNetlistStandardReader::read_pin (db::Netlist * /*netlist*/, db::LayoutTo
   }
 
   size_t pin_id = circuit->add_pin (pin).id ();
+  //  NOTE: because we identify pins by their order and not by ID we need to ensure the pin IDs are
+  //  generated sequentially.
+  tl_assert (circuit->pin_count () == pin_id + 1);
   if (net) {
     circuit->connect_pin (pin_id, net);
   }
diff --git a/src/db/db/dbLayoutToNetlistWriter.cc b/src/db/db/dbLayoutToNetlistWriter.cc
index bdeeebb91..4dc227ae4 100644
--- a/src/db/db/dbLayoutToNetlistWriter.cc
+++ b/src/db/db/dbLayoutToNetlistWriter.cc
@@ -561,7 +561,8 @@ void std_writer_impl<Keys>::write (const db::SubCircuit &subcircuit, std::map<co
     *mp_stream << indent << indent2 << Keys::property_key << "(" << p->first.to_parsable_string () << " " << p->second.to_parsable_string () << ")" << endl;
   }
 
-  for (db::Circuit::const_pin_iterator p = subcircuit.circuit_ref ()->begin_pins (); p != subcircuit.circuit_ref ()->end_pins (); ++p) {
+  unsigned int pin_id = 0;
+  for (db::Circuit::const_pin_iterator p = subcircuit.circuit_ref ()->begin_pins (); p != subcircuit.circuit_ref ()->end_pins (); ++p, ++pin_id) {
     const db::Net *net = subcircuit.net_for_pin (p->id ());
     if (net) {
       if (separate_lines) {
@@ -569,7 +570,7 @@ void std_writer_impl<Keys>::write (const db::SubCircuit &subcircuit, std::map<co
       } else {
         *mp_stream << " ";
       }
-      *mp_stream << Keys::pin_key << "(" << tl::to_string (p->id ()) << " " << net2id [net] << ")";
+      *mp_stream << Keys::pin_key << "(" << tl::to_string (pin_id) << " " << net2id [net] << ")";
       if (separate_lines) {
         *mp_stream << endl;
       }
diff --git a/src/db/db/dbLayoutVsSchematicWriter.cc b/src/db/db/dbLayoutVsSchematicWriter.cc
index 251afb60e..14a2b1c13 100644
--- a/src/db/db/dbLayoutVsSchematicWriter.cc
+++ b/src/db/db/dbLayoutVsSchematicWriter.cc
@@ -146,7 +146,7 @@ std::string ion_to_s (const Obj *obj)
   }
 }
 
-std::string net_id_to_s (const db::Net *net, const std::map<const db::Net *, unsigned int> &net2id)
+static std::string net_id_to_s (const db::Net *net, const std::map<const db::Net *, unsigned int> &net2id)
 {
   if (net) {
     std::map<const db::Net *, unsigned int>::const_iterator i = net2id.find (net);
@@ -157,6 +157,25 @@ std::string net_id_to_s (const db::Net *net, const std::map<const db::Net *, uns
   }
 }
 
+static void build_pin_index_map (const db::Circuit *c, std::map<const db::Pin *, unsigned int> &pin2index)
+{
+  size_t pi = 0;
+  for (db::Circuit::const_pin_iterator p = c->begin_pins (); p != c->end_pins (); ++p, ++pi) {
+    pin2index.insert (std::make_pair (p.operator-> (), pi));
+  }
+}
+
+static std::string pin_id_to_s (const db::Pin *pin, const std::map<const db::Pin *, unsigned int> &pin2index)
+{
+  if (pin) {
+    std::map<const db::Pin *, unsigned int>::const_iterator i = pin2index.find (pin);
+    tl_assert (i != pin2index.end ());
+    return tl::to_string (i->second);
+  } else {
+    return "()";
+  }
+}
+
 template <class Keys>
 std::string std_writer_impl<Keys>::message_to_s (const std::string &msg)
 {
@@ -200,8 +219,12 @@ void std_writer_impl<Keys>::write (const db::NetlistCrossReference *xref)
       stream () << indent1 << indent2 << Keys::net_key << "(" << net_id_to_s (n->pair.first, m_net2id_per_circuit_a [c->first]) << " " << net_id_to_s (n->pair.second, m_net2id_per_circuit_b [c->second]) << status_to_s (n->status) << message_to_s (n->msg) << ")" << endl;
     }
 
+    std::map<const db::Pin *, unsigned int> pin2index_a, pin2index_b;
+    build_pin_index_map (c->first, pin2index_a);
+    build_pin_index_map (c->second, pin2index_b);
+
     for (db::NetlistCrossReference::PerCircuitData::pin_pairs_const_iterator n = pcd->pins.begin (); n != pcd->pins.end (); ++n) {
-      stream () << indent1 << indent2 << Keys::pin_key << "(" << ion_to_s (n->pair.first) << " " << ion_to_s (n->pair.second) << status_to_s (n->status) << message_to_s (n->msg) << ")" << endl;
+      stream () << indent1 << indent2 << Keys::pin_key << "(" << pin_id_to_s (n->pair.first, pin2index_a) << " " << pin_id_to_s (n->pair.second, pin2index_b) << status_to_s (n->status) << message_to_s (n->msg) << ")" << endl;
     }
 
     for (db::NetlistCrossReference::PerCircuitData::device_pairs_const_iterator n = pcd->devices.begin (); n != pcd->devices.end (); ++n) {