diff --git a/src/db/db/dbRegionLocalOperations.cc b/src/db/db/dbRegionLocalOperations.cc
index feaabf569..f60484eb6 100644
--- a/src/db/db/dbRegionLocalOperations.cc
+++ b/src/db/db/dbRegionLocalOperations.cc
@@ -2381,8 +2381,11 @@ PolygonToEdgeLocalOperation::do_compute_local (db::Layout * /*layout*/, db::Cell
 
     db::properties_id_type prop_id = shapes_by_prop_id->first;
 
+    ep.clear ();
+
+    size_t p = 0;
     for (auto s = shapes_by_prop_id->second.first.begin (); s != shapes_by_prop_id->second.first.end (); ++s) {
-      ep.insert (**s);
+      ep.insert (**s, p++);
     }
 
     db::property_injector<db::Edge, std::unordered_set<db::EdgeWithProperties> > results_with_properties (&results.front (), prop_id);
@@ -2395,7 +2398,6 @@ PolygonToEdgeLocalOperation::do_compute_local (db::Layout * /*layout*/, db::Cell
 
     } else {
 
-      // @@@ that's not correct, isn't it?
       //  With intruders: to compute our local contribution we take the edges without and with intruders
       //  and deliver what is in both sets
 
@@ -2407,18 +2409,19 @@ PolygonToEdgeLocalOperation::do_compute_local (db::Layout * /*layout*/, db::Cell
 
       ep.clear ();
 
-      for (auto s = interactions.begin_subjects (); s != interactions.end_subjects (); ++s) {
-        ep.insert (s->second);
+      size_t p = 0;
+      for (auto s = shapes_by_prop_id->second.first.begin (); s != shapes_by_prop_id->second.first.end (); ++s) {
+        ep.insert (**s, ++p);
       }
-      for (auto i = interactions.begin_intruders (); i != interactions.end_intruders (); ++i) {
-        ep.insert (i->second.second);
+      for (auto s = shapes_by_prop_id->second.second.begin (); s != shapes_by_prop_id->second.second.end (); ++s) {
+        ep.insert (*(s->second), ++p);
       }
 
       std::vector<Edge> edges2;
       db::EdgeContainer ec2 (edges2);
       ep.process (ec2, op);
 
-      //  Runs the boolean AND between the result with and without intruders
+      //  Runs the boolean AND between the result with and without intruders - this identifies outside edges
 
       db::box_scanner<db::Edge, size_t> scanner;
       scanner.reserve (edges1.size () + edges2.size ());
diff --git a/src/drc/unit_tests/drcSimpleTests.cc b/src/drc/unit_tests/drcSimpleTests.cc
index ab6532d72..9928e45de 100644
--- a/src/drc/unit_tests/drcSimpleTests.cc
+++ b/src/drc/unit_tests/drcSimpleTests.cc
@@ -2133,3 +2133,13 @@ TEST(150d_optimized_separation)
 {
   run_test (_this, "150", true);
 }
+
+TEST(151_edges_from_region_with_properties)
+{
+  run_test (_this, "151", false);
+}
+
+TEST(151d_edges_from_region_with_properties)
+{
+  run_test (_this, "151", true);
+}
diff --git a/testdata/drc/drcSimpleTests_151.drc b/testdata/drc/drcSimpleTests_151.drc
new file mode 100644
index 000000000..154464951
--- /dev/null
+++ b/testdata/drc/drcSimpleTests_151.drc
@@ -0,0 +1,14 @@
+source $drc_test_source
+target $drc_test_target
+
+if $drc_test_deep
+  deep
+end
+
+deep
+
+l1 = input(1, 0, enable_props)
+l1.output(1, 0)
+
+l1.edges.output(100, 0)
+
diff --git a/testdata/drc/drcSimpleTests_151.gds b/testdata/drc/drcSimpleTests_151.gds
new file mode 100644
index 000000000..9750b9468
Binary files /dev/null and b/testdata/drc/drcSimpleTests_151.gds differ
diff --git a/testdata/drc/drcSimpleTests_au151.gds b/testdata/drc/drcSimpleTests_au151.gds
new file mode 100644
index 000000000..75622fd4b
Binary files /dev/null and b/testdata/drc/drcSimpleTests_au151.gds differ
diff --git a/testdata/drc/drcSimpleTests_au151d.gds b/testdata/drc/drcSimpleTests_au151d.gds
new file mode 100644
index 000000000..75622fd4b
Binary files /dev/null and b/testdata/drc/drcSimpleTests_au151d.gds differ