diff --git a/masque/file/dxf.py b/masque/file/dxf.py
index db01f51..0c19b5a 100644
--- a/masque/file/dxf.py
+++ b/masque/file/dxf.py
@@ -212,8 +212,10 @@ def _read_block(block: ezdxf.layouts.BlockLayout | ezdxf.layouts.Modelspace) ->
         if isinstance(element, LWPolyline | Polyline):
             if isinstance(element, LWPolyline):
                 points = numpy.asarray(element.get_points())
-            elif isinstance(element, Polyline):
+                is_closed = element.closed
+            else:
                 points = numpy.asarray([pp.xyz for pp in element.points()])
+                is_closed = element.is_closed
             attr = element.dxfattribs()
             layer = attr.get('layer', DEFAULT_LAYER)
 
@@ -233,7 +235,6 @@ def _read_block(block: ezdxf.layouts.BlockLayout | ezdxf.layouts.Modelspace) ->
             if width == 0:
                 width = attr.get('const_width', 0)
 
-            is_closed = element.closed
             verts = points[:, :2]
             if is_closed and (len(verts) < 2 or not numpy.allclose(verts[0], verts[-1])):
                 verts = numpy.vstack((verts, verts[0]))
diff --git a/masque/test/test_dxf.py b/masque/test/test_dxf.py
index e6e6e7e..0c0a1a3 100644
--- a/masque/test/test_dxf.py
+++ b/masque/test/test_dxf.py
@@ -1,5 +1,6 @@
-
+import io
 import numpy
+import ezdxf
 from numpy.testing import assert_allclose
 from pathlib import Path
 
@@ -109,3 +110,20 @@ def test_dxf_manhattan_precision(tmp_path: Path):
     target_name = next(k for k in read_top.refs if k.upper() == "SUB")
     ref = read_top.refs[target_name][0]
     assert isinstance(ref.repetition, Grid), "Grid should be preserved for 90-degree rotation"
+
+
+def test_dxf_read_legacy_polyline() -> None:
+    doc = ezdxf.new()
+    msp = doc.modelspace()
+    msp.add_polyline2d([(0, 0), (10, 0), (10, 10)], dxfattribs={"layer": "legacy"}).close(True)
+
+    stream = io.StringIO()
+    doc.write(stream)
+    stream.seek(0)
+
+    read_lib, _ = dxf.read(stream)
+    top_pat = read_lib.get("Model") or list(read_lib.values())[0]
+
+    polys = [shape for shape in top_pat.shapes["legacy"] if isinstance(shape, Polygon)]
+    assert len(polys) == 1
+    assert_allclose(polys[0].vertices, [[0, 0], [10, 0], [10, 10]])