diff --git a/sw/qa/extras/ooxmlexport/data/tdf170438_dropdown.odt b/sw/qa/extras/ooxmlexport/data/tdf170438_dropdown.odt
new file mode 100644
index 000000000000..02bbe360bf25
Binary files /dev/null and b/sw/qa/extras/ooxmlexport/data/tdf170438_dropdown.odt differ
diff --git a/sw/qa/extras/ooxmlexport/ooxmlexport25.cxx b/sw/qa/extras/ooxmlexport/ooxmlexport25.cxx
index 2ea0d1a6a50f..110211a7c2c9 100644
--- a/sw/qa/extras/ooxmlexport/ooxmlexport25.cxx
+++ b/sw/qa/extras/ooxmlexport/ooxmlexport25.cxx
@@ -150,6 +150,18 @@ DECLARE_OOXMLEXPORT_TEST(testTdf165478_bottomAligned, "tdf165478_bottomAligned.d
     CPPUNIT_ASSERT_EQUAL(sal_Int32(1887), nFlyTop);
 }
 
+CPPUNIT_TEST_FIXTURE(Test, testTdf170438_dropdown)
+{
+    createSwDoc("tdf170438_dropdown.odt");
+
+    saveAndReload(TestFilter::DOCX);
+
+    xmlDocUniquePtr pXmlDoc = parseExport(u"word/document.xml"_ustr);
+    // MS Word reports document as corrupt if displayText is empty
+    assertXPath(pXmlDoc, "//w:listItem[1]", "displayText", u" ");
+    assertXPath(pXmlDoc, "//w:listItem[1]", "value", u""); // value may be empty
+}
+
 CPPUNIT_TEST_FIXTURE(Test, testTdf170389_manyTabstops)
 {
     createSwDoc("tdf170389_manyTabstops.odt");
diff --git a/sw/source/filter/ww8/docxattributeoutput.cxx b/sw/source/filter/ww8/docxattributeoutput.cxx
index ddcc2c629a2b..e1a2e450ee14 100644
--- a/sw/source/filter/ww8/docxattributeoutput.cxx
+++ b/sw/source/filter/ww8/docxattributeoutput.cxx
@@ -2882,9 +2882,10 @@ void DocxAttributeOutput::WriteSdtDropDownStart(
     for (auto const& rItem : rListItems)
     {
         auto const item(OUStringToOString(rItem, RTL_TEXTENCODING_UTF8));
+        OString sDisplayText = item.isEmpty() ? " "_ostr : item; // displayText must not be empty
         m_pSerializer->singleElementNS(XML_w, XML_listItem,
                 FSNS(XML_w, XML_value), item,
-                FSNS(XML_w, XML_displayText), item);
+                FSNS(XML_w, XML_displayText), sDisplayText);
     }
 
     m_pSerializer->endElementNS(XML_w, XML_dropDownList);
@@ -5894,8 +5895,9 @@ void DocxAttributeOutput::WritePostponedFormControl(const SdrObject* pObject)
 
         for (const auto& rItem : aItems)
         {
+            OUString sDisplayText = rItem.isEmpty() ? " " : rItem; // displayText must not be empty
             m_pSerializer->singleElementNS(XML_w, XML_listItem,
-                                           FSNS(XML_w, XML_displayText), rItem,
+                                           FSNS(XML_w, XML_displayText), sDisplayText,
                                            FSNS(XML_w, XML_value), rItem);
         }