diff --git a/packages/markitdown-ocr/tests/test_docx_converter.py b/packages/markitdown-ocr/tests/test_docx_converter.py
index 2538206ded..f9df439c13 100644
--- a/packages/markitdown-ocr/tests/test_docx_converter.py
+++ b/packages/markitdown-ocr/tests/test_docx_converter.py
@@ -226,6 +226,56 @@ def test_docx_no_ocr_service_no_tags() -> None:
     assert "[End OCR]*" not in md
 
 
+@pytest.mark.parametrize("double_strike", [False, True])
+@pytest.mark.parametrize("use_ocr", [False, True])
+def test_docx_styles_with_redundant_default_namespace(
+    svc: MockOCRService, use_ocr: bool, double_strike: bool
+) -> None:
+    path = TEST_DATA_DIR / "docx_image_middle.docx"
+    if not path.exists():
+        pytest.skip(f"Test file not found: {path}")
+    original = path.read_bytes()
+    fixture = io.BytesIO()
+    namespace = "http://schemas.openxmlformats.org/wordprocessingml/2006/main"
+    declaration = f'xmlns:w="{namespace}"'.encode("utf-8")
+    with zipfile.ZipFile(io.BytesIO(original)) as source, zipfile.ZipFile(
+        fixture, "w"
+    ) as target:
+        for item in source.infolist():
+            content = source.read(item)
+            if item.filename == "word/styles.xml":
+                if double_strike:
+                    assert content.count(b"</w:styles>") == 1
+                    content = content.replace(
+                        b"</w:styles>",
+                        b'<w:style w:type="character" w:styleId="DoubleStrike">'
+                        b'<w:name w:val="Double Strike"/>'
+                        b'<w:rPr><w:dstrike w:val="1"/></w:rPr>'
+                        b"</w:style></w:styles>",
+                        1,
+                    )
+                assert content.count(declaration) == 1
+                content = content.replace(
+                    declaration, declaration + f' xmlns="{namespace}"'.encode(), 1
+                )
+            target.writestr(item, content)
+
+    converter = DocxConverterWithOCR()
+    service = svc if use_ocr else None
+    expected = converter.convert(
+        io.BytesIO(original), StreamInfo(extension=".docx"), ocr_service=service
+    ).markdown
+    fixture.seek(0)
+    actual = converter.convert(
+        fixture, StreamInfo(extension=".docx"), ocr_service=service
+    ).markdown
+
+    assert "# Introduction" in actual
+    assert actual == expected
+    if use_ocr:
+        assert _MOCK_TEXT in actual
+
+
 # ---------------------------------------------------------------------------
 # Underlined runs survive both the OCR and the non-OCR mammoth paths
 # ---------------------------------------------------------------------------
diff --git a/packages/markitdown/src/markitdown/converter_utils/docx/pre_process.py b/packages/markitdown/src/markitdown/converter_utils/docx/pre_process.py
index 46847a2a34..c6dc303414 100644
--- a/packages/markitdown/src/markitdown/converter_utils/docx/pre_process.py
+++ b/packages/markitdown/src/markitdown/converter_utils/docx/pre_process.py
@@ -216,15 +216,35 @@ def _pre_process_styles(content: bytes) -> bytes:
     to ``paragraph``, so the attribute is filled in rather than dropping the
     style, which would discard its formatting (a heading would be emitted as
     plain body text). A style with no ``w:styleId`` cannot be referenced by the
-    document body, so it is removed.
+    document body, so it is removed. Double strikethrough is normalized to
+    single strikethrough in the same namespace-aware pass.
+
+    Match elements and attributes by namespace URI, preserving their qualified
+    names when repairing the XML. Return the original bytes if no repair is needed.
     """
-    soup = BeautifulSoup(content, features="xml")
-    for tag in soup.find_all("w:style"):
-        if not tag.has_attr("w:styleId"):
-            tag.decompose()
-        elif not tag.has_attr("w:type"):
-            tag["w:type"] = "paragraph"
-    return str(soup).encode()
+    from lxml import etree
+
+    namespace = "{http://schemas.openxmlformats.org/wordprocessingml/2006/main}"
+    parser = etree.XMLParser(resolve_entities=False, no_network=True)
+    root = etree.fromstring(content, parser=parser)
+    changed = False
+
+    for style in root.findall(namespace + "style"):
+        if namespace + "styleId" not in style.attrib:
+            root.remove(style)
+            changed = True
+        elif namespace + "type" not in style.attrib:
+            style.set(namespace + "type", "paragraph")
+            changed = True
+
+    for strike in root.iter(namespace + "dstrike"):
+        strike.tag = namespace + "strike"
+        changed = True
+
+    if not changed:
+        return content
+
+    return etree.tostring(root.getroottree(), encoding="utf-8", xml_declaration=True)
 
 
 def pre_process_docx(input_docx: BinaryIO) -> BinaryIO:
@@ -250,7 +270,7 @@ def pre_process_docx(input_docx: BinaryIO) -> BinaryIO:
         "word/document.xml": (_pre_process_strike, _pre_process_math),
         "word/footnotes.xml": (_pre_process_strike, _pre_process_math),
         "word/endnotes.xml": (_pre_process_strike, _pre_process_math),
-        "word/styles.xml": (_pre_process_strike, _pre_process_styles),
+        "word/styles.xml": (_pre_process_styles,),
     }
     with zipfile.ZipFile(input_docx, mode="r") as zip_input:
         files = {name: zip_input.read(name) for name in zip_input.namelist()}
diff --git a/packages/markitdown/tests/test_docx_styles.py b/packages/markitdown/tests/test_docx_styles.py
new file mode 100644
index 0000000000..218fe03c5d
--- /dev/null
+++ b/packages/markitdown/tests/test_docx_styles.py
@@ -0,0 +1,152 @@
+"""DOCX stylesheet repair must preserve namespace-qualified attributes."""
+
+import io
+from pathlib import Path
+import re
+import zipfile
+
+from lxml import etree
+import pytest
+
+from markitdown import MarkItDown, StreamInfo
+from markitdown.converter_utils.docx.pre_process import _pre_process_styles
+
+
+WORD_NAMESPACE = "http://schemas.openxmlformats.org/wordprocessingml/2006/main"
+W = f"{{{WORD_NAMESPACE}}}"
+TEST_DOCX = Path(__file__).parent / "test_files" / "test.docx"
+
+
+@pytest.mark.parametrize("double_strike", [False, True])
+@pytest.mark.parametrize("missing_type", [False, True])
+def test_docx_styles_with_redundant_default_namespace(
+    missing_type: bool, double_strike: bool
+) -> None:
+    markitdown = MarkItDown()
+    expected = markitdown.convert(TEST_DOCX).markdown
+    fixture = io.BytesIO()
+    declaration = f'xmlns:w="{WORD_NAMESPACE}"'.encode("utf-8")
+
+    with zipfile.ZipFile(TEST_DOCX) as source, zipfile.ZipFile(fixture, "w") as target:
+        for item in source.infolist():
+            content = source.read(item)
+            if item.filename == "word/styles.xml":
+                if double_strike:
+                    assert content.count(b"</w:styles>") == 1
+                    content = content.replace(
+                        b"</w:styles>",
+                        b'<w:style w:type="character" w:styleId="DoubleStrike">'
+                        b'<w:name w:val="Double Strike"/>'
+                        b'<w:rPr><w:dstrike w:val="1"/></w:rPr>'
+                        b"</w:style></w:styles>",
+                        1,
+                    )
+                assert content.count(declaration) == 1
+                content = content.replace(
+                    declaration,
+                    declaration + f' xmlns="{WORD_NAMESPACE}"'.encode("utf-8"),
+                    1,
+                )
+                if missing_type:
+                    content, count = re.subn(
+                        rb'<w:style\s+w:type="[^"]+"(\s+w:styleId="1")',
+                        rb"<w:style\1",
+                        content,
+                    )
+                    assert count == 1
+                styles = etree.fromstring(content).findall(W + "style")
+                assert styles
+                assert all(W + "styleId" in style.attrib for style in styles)
+            target.writestr(item, content)
+
+    fixture.seek(0)
+    actual = markitdown.convert_stream(
+        fixture, stream_info=StreamInfo(extension=".docx")
+    ).markdown
+
+    assert "# Abstract" in actual
+    assert actual == expected
+
+
+@pytest.fixture(params=["w", "word"])
+def styles_xml(request: pytest.FixtureRequest) -> bytes:
+    prefix = request.param
+    return f"""<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<{prefix}:styles xmlns:{prefix}="{WORD_NAMESPACE}" xmlns="{WORD_NAMESPACE}"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    xmlns:w14="http://schemas.microsoft.com/office/word/2010/wordml"
+    mc:Ignorable="w14">
+  <{prefix}:style {prefix}:type="paragraph" {prefix}:styleId="Normal">
+    <{prefix}:name {prefix}:val="Normal"/>
+  </{prefix}:style>
+</{prefix}:styles>""".encode(
+        "utf-8"
+    )
+
+
+def test_valid_styles_are_returned_unchanged(styles_xml: bytes) -> None:
+    assert _pre_process_styles(styles_xml) == styles_xml
+
+
+def test_missing_type_repair_preserves_namespaces(styles_xml: bytes) -> None:
+    malformed, count = re.subn(rb'\s+(?:w|word):type="paragraph"', b"", styles_xml)
+    assert count == 1
+    original = etree.fromstring(styles_xml)
+
+    repaired = etree.fromstring(_pre_process_styles(malformed))
+
+    assert repaired.nsmap == original.nsmap
+    assert repaired.attrib == original.attrib
+    style = repaired.find(W + "style")
+    assert style is not None
+    assert style.attrib == {W + "type": "paragraph", W + "styleId": "Normal"}
+    name = style.find(W + "name")
+    assert name is not None
+    assert name.attrib == {W + "val": "Normal"}
+
+
+def test_styles_without_ids_are_removed(styles_xml: bytes) -> None:
+    malformed, count = re.subn(rb'\s+(?:w|word):styleId="Normal"', b"", styles_xml)
+    assert count == 1
+
+    repaired = etree.fromstring(_pre_process_styles(malformed))
+
+    assert repaired.findall(W + "style") == []
+
+
+@pytest.mark.parametrize("value", [None, "0", "1"])
+@pytest.mark.parametrize("missing_type", [False, True])
+def test_style_strike_repair_preserves_namespaces(
+    styles_xml: bytes, value: str | None, missing_type: bool
+) -> None:
+    original = etree.fromstring(styles_xml)
+    style = original.find(W + "style")
+    assert style is not None
+    if missing_type:
+        del style.attrib[W + "type"]
+    properties = etree.SubElement(style, W + "rPr")
+    strike = etree.SubElement(properties, W + "dstrike")
+    if value is not None:
+        strike.set(W + "val", value)
+    etree.SubElement(properties, W + "b")
+
+    repaired = etree.fromstring(_pre_process_styles(etree.tostring(original)))
+
+    assert repaired.nsmap == original.nsmap
+    assert repaired.attrib == original.attrib
+    style = repaired.find(W + "style")
+    assert style is not None
+    assert style.attrib == {W + "type": "paragraph", W + "styleId": "Normal"}
+    assert repaired.find(".//" + W + "dstrike") is None
+    strike = style.find(f"{W}rPr/{W}strike")
+    assert strike is not None
+    assert strike.attrib == ({} if value is None else {W + "val": value})
+    assert style.find(f"{W}rPr/{W}b") is not None
+
+
+def test_other_namespace_dstrike_is_unchanged(styles_xml: bytes) -> None:
+    original = etree.fromstring(styles_xml)
+    etree.SubElement(original, "{urn:extension}dstrike")
+    content = etree.tostring(original)
+
+    assert _pre_process_styles(content) == content