diff --git a/src/plugins/streamers/oasis/db_plugin/dbOASISWriter.cc b/src/plugins/streamers/oasis/db_plugin/dbOASISWriter.cc
index 77f82f653..8d486117e 100644
--- a/src/plugins/streamers/oasis/db_plugin/dbOASISWriter.cc
+++ b/src/plugins/streamers/oasis/db_plugin/dbOASISWriter.cc
@@ -1998,10 +1998,10 @@ OASISWriter::write (const db::CellInstArray &inst, db::properties_id_type prop_i
 
     if (rep != db::Repetition ()) {
       for (db::RepetitionIterator r = rep.begin (); ! r.at_end (); ++r) {
-        write_inst_with_rep (inst, prop_id, *r, array_rep);
+        write_inst_with_rep (inst, prop_id, *r + po, array_rep);
       }
     } else {
-      write_inst_with_rep (inst, prop_id, db::Vector (), array_rep);
+      write_inst_with_rep (inst, prop_id, po, array_rep);
     }
 
   } else if (inst.is_regular_array (a, b, amax, bmax) && (amax > 1 || bmax > 1)) {
diff --git a/src/plugins/streamers/oasis/unit_tests/dbOASISWriterTests.cc b/src/plugins/streamers/oasis/unit_tests/dbOASISWriterTests.cc
index b7d70b664..c632840b3 100644
--- a/src/plugins/streamers/oasis/unit_tests/dbOASISWriterTests.cc
+++ b/src/plugins/streamers/oasis/unit_tests/dbOASISWriterTests.cc
@@ -1805,3 +1805,45 @@ TEST(119_WithAndWithoutContext)
   }
 
 }
+
+TEST(120_IrregularInstRepetitions)
+{
+  db::Manager m (false);
+  db::Layout g (&m);
+
+  db::cell_index_type top = g.add_cell ("TOP");
+  db::cell_index_type c1 = g.add_cell ("C1");
+
+  db::Vector pts[3] = { db::Vector (0, 10), db::Vector (0, 20), db::Vector (0, 30) };
+
+  unsigned int l1 = g.insert_layer (db::LayerProperties (1, 0));
+  g.cell (c1).shapes (l1).insert (db::Box (-5, -5, 5, 5));
+  db::iterated_array<db::Coord> *reps = new db::iterated_array<db::Coord> (pts + 0, pts + 3);
+  g.cell (top).shapes (l1).insert (db::array<db::Box, db::UnitTrans> (db::Box (-5, -5, 5, 5), db::UnitTrans (), reps));
+
+  db::iterated_array<db::Coord> *rep = new db::iterated_array<db::Coord> (pts + 0, pts + 3);
+  db::CellInstArray ci1 (db::CellInst (c1), db::Trans (db::Vector (10, 0)), rep);
+  g.cell (top).insert (ci1);
+
+  std::string tmp_file = tl::TestBase::tmp_file (tl::sprintf ("tmp_dbOASISWriter120.oas"));
+
+  {
+    tl::OutputStream out (tmp_file);
+    db::SaveLayoutOptions options;
+    options.set_format ("OASIS");
+    db::Writer writer (options);
+    writer.write (g, out);
+  }
+
+  {
+    tl::InputStream in (tmp_file);
+    db::Reader reader (in);
+    db::Layout gg;
+    reader.set_warnings_as_errors (true);
+    reader.read (gg);
+
+    CHECKPOINT ();
+    db::compare_layouts (_this, gg, tl::testdata () + "/oasis/dbOASISWriter120_au.gds", db::NoNormalization);
+  }
+
+}
diff --git a/testdata/oasis/dbOASISWriter120_au.gds b/testdata/oasis/dbOASISWriter120_au.gds
new file mode 100644
index 000000000..39355df92
Binary files /dev/null and b/testdata/oasis/dbOASISWriter120_au.gds differ