diff --git a/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.cc b/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.cc
index 4a35ba4c9..459a3224e 100644
--- a/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.cc
+++ b/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.cc
@@ -822,7 +822,7 @@ DEFImporter::read_nets (db::Layout &layout, db::Cell &design, double scale, bool
     std::string net = get ();
     std::string nondefaultrule;
     std::string stored_netname, stored_nondefaultrule;
-    db::properties_id_type stored_prop_id;
+    db::properties_id_type stored_prop_id = 0;
     bool in_subnet = false;
 
     db::properties_id_type prop_id = 0;
@@ -1421,10 +1421,26 @@ DEFImporter::read_pins (db::Layout &layout, db::Cell &design, double scale)
   }
 }
 
+db::Cell &
+DEFImporter::ensure_fill_cell (db::Layout &layout, db::Cell &design, db::Cell *&fill_cell)
+{
+  if (! fill_cell) {
+
+    std::string fill_cell_name = m_design_name + "_DEF_FILL";
+    fill_cell = &layout.cell (reader_state ()->make_cell (layout, fill_cell_name));
+
+    design.insert (db::CellInstArray (fill_cell->cell_index (), db::Trans ()));
+
+  }
+
+  return *fill_cell;
+}
+
 void
 DEFImporter::read_fills (db::Layout &layout, db::Cell &design, double scale)
 {
   std::map <std::pair<std::string, unsigned int>, std::vector <db::Polygon> > geometry;
+  db::Cell *fill_cell = 0;
 
   while (test ("-")) {
 
@@ -1495,7 +1511,7 @@ DEFImporter::read_fills (db::Layout &layout, db::Cell &design, double scale)
       if (! dl.empty ()) {
         for (std::vector<db::Polygon>::const_iterator p = polygons.begin (); p != polygons.end (); ++p) {
           for (std::set<unsigned int>::const_iterator l = dl.begin (); l != dl.end (); ++l) {
-            design.shapes (*l).insert (*p);
+            ensure_fill_cell (layout, design, fill_cell).shapes (*l).insert (*p);
           }
         }
       }
@@ -1535,7 +1551,7 @@ DEFImporter::read_fills (db::Layout &layout, db::Cell &design, double scale)
           std::string nondefaultrule;
           db::Cell *cell = reader_state ()->via_cell (vn, nondefaultrule, layout, mask_bottom, mask_cut, mask_top, &m_lef_importer);
           if (cell) {
-            design.insert (db::CellInstArray (db::CellInst (cell->cell_index ()), db::Trans (pt)));
+            ensure_fill_cell (layout, design, fill_cell).insert (db::CellInstArray (db::CellInst (cell->cell_index ()), db::Trans (pt)));
           }
         } else {
           warn (tl::to_string (tr ("Invalid via name: ")) + vn);
@@ -1670,6 +1686,7 @@ DEFImporter::do_read (db::Layout &layout)
 
   m_via_desc = m_lef_importer.vias ();
   m_styles.clear ();
+  m_design_name.clear ();
 
   db::Cell &design = layout.cell (reader_state ()->make_cell (layout, top_id));
 
@@ -1685,8 +1702,8 @@ DEFImporter::do_read (db::Layout &layout)
 
     } else if (test ("DESIGN")) {
 
-      std::string cn = get ();
-      reader_state ()->rename_cell (layout, top_id, cn);
+      m_design_name = get ();
+      reader_state ()->rename_cell (layout, top_id, m_design_name);
 
       expect (";");
 
diff --git a/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.h b/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.h
index 43772e26b..45a42f60f 100644
--- a/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.h
+++ b/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.h
@@ -72,6 +72,7 @@ private:
   std::map<std::string, ViaDesc> m_via_desc;
   std::map<int, db::Polygon> m_styles;
   std::vector<std::string> m_component_maskshift;
+  std::string m_design_name;
 
   void read_polygon (db::Polygon &poly, double scale);
   void read_rect (db::Polygon &poly, double scale);
@@ -86,6 +87,7 @@ private:
   void read_vias (db::Layout &layout, db::Cell &design, double scale);
   void read_pins (db::Layout &layout, db::Cell &design, double scale);
   void read_fills (db::Layout &layout, db::Cell &design, double scale);
+  db::Cell &ensure_fill_cell (db::Layout &layout, db::Cell &design, db::Cell *&fill_cell);
   void read_styles (double scale);
   void read_components (Layout &layout, std::list<std::pair<std::string, db::CellInstArray> > &instances, double scale);
   void read_single_net (std::string &nondefaultrule, db::Layout &layout, db::Cell &design, double scale, properties_id_type prop_id, bool specialnets);
diff --git a/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFImportTests.cc b/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFImportTests.cc
index 6646fbe6d..94f92050c 100644
--- a/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFImportTests.cc
+++ b/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFImportTests.cc
@@ -429,7 +429,7 @@ TEST(def16)
   //  (complete example)
   db::LEFDEFReaderOptions opt = default_options ();
   opt.set_macro_resolution_mode (1);
-  run_test (_this, "def16", "lef:a.lef+lef:tech.lef+def:a.def", "au_4.oas.gz", opt);
+  run_test (_this, "def16", "lef:a.lef+lef:tech.lef+def:a.def", "au_4b.oas.gz", opt);
 }
 
 TEST(100)
diff --git a/testdata/lefdef/fill/simple_au.oas.gz b/testdata/lefdef/fill/simple_au.oas.gz
index c6ca9c9eb..8ff171590 100644
Binary files a/testdata/lefdef/fill/simple_au.oas.gz and b/testdata/lefdef/fill/simple_au.oas.gz differ
diff --git a/testdata/lefdef/fill/with_mask_au.oas.gz b/testdata/lefdef/fill/with_mask_au.oas.gz
index 946e28973..8c854748f 100644
Binary files a/testdata/lefdef/fill/with_mask_au.oas.gz and b/testdata/lefdef/fill/with_mask_au.oas.gz differ