diff --git a/Lib/test/test_sax.py b/Lib/test/test_sax.py
index eda4e6a46df437a..92443907924bcc2 100644
--- a/Lib/test/test_sax.py
+++ b/Lib/test/test_sax.py
@@ -19,6 +19,7 @@
 from io import BytesIO, StringIO
 import codecs
 import os.path
+import pyexpat
 import shutil
 import sys
 from urllib.error import URLError
@@ -1214,6 +1215,30 @@ def test_expat_incremental_reset(self):
 
         self.assertEqual(result.getvalue(), start + b"<doc>text</doc>")
 
+    def test_expat_incremental_reparse_deferral(self):
+        result = BytesIO()
+        xmlgen = XMLGenerator(result)
+        parser = create_parser()
+        parser.setContentHandler(xmlgen)
+
+        # This artificial chunking triggers reparse deferral with Expat >=2.6.0
+        parser.feed("<doc ")
+        parser.feed(">")
+
+        if pyexpat.version_info >= (2, 6, 0):
+            self.assertEqual(result.getvalue(), start)
+        else:
+            self.assertEqual(result.getvalue(), start + b"<doc>")
+
+        parser.flush()  # no-op for Expat <2.6.0
+
+        self.assertEqual(result.getvalue(), start + b"<doc>")
+
+        parser.feed("</doc>")
+        parser.close()
+
+        self.assertEqual(result.getvalue(), start + b"<doc></doc>")
+
     # ===== Locator support
 
     def test_expat_locator_noinfo(self):