diff --git a/Doc/library/optparse.rst b/Doc/library/optparse.rst
index 09416f12ad45c2..df0f2a4df4db45 100644
--- a/Doc/library/optparse.rst
+++ b/Doc/library/optparse.rst
@@ -16,15 +16,12 @@ Choosing an argument parsing library
 The standard library includes three argument parsing libraries:
 
 * :mod:`getopt`: a module that closely mirrors the procedural C ``getopt`` API.
-  Included in the standard library since before the initial Python 1.0 release.
 * :mod:`!optparse`: a declarative replacement for ``getopt`` that
   provides equivalent functionality without requiring each application
-  to implement its own procedural option parsing logic. Included
-  in the standard library since the Python 2.3 release.
+  to implement its own procedural option parsing logic.
 * :mod:`argparse`: a more opinionated alternative to ``optparse`` that
   provides more functionality by default, at the expense of reduced application
-  flexibility in controlling exactly how arguments are processed. Included in
-  the standard library since the Python 2.7 and Python 3.2 releases.
+  flexibility in controlling exactly how arguments are processed.
 
 In the absence of more specific argument parsing design constraints, :mod:`argparse`
 is the recommended choice for implementing command line applications, as it offers
diff --git a/Lib/optparse.py b/Lib/optparse.py
index ae6737a3d13942..70ca3b38b021a5 100644
--- a/Lib/optparse.py
+++ b/Lib/optparse.py
@@ -1,12 +1,5 @@
 """A powerful, extensible, and easy-to-use option parser.
 
-By Greg Ward <gward@python.net>
-
-Originally distributed as Optik.
-
-For support, use the optik-users@lists.sourceforge.net mailing list
-(http://lists.sourceforge.net/lists/listinfo/optik-users).
-
 Simple usage example:
 
    from optparse import OptionParser
diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index 205916579b5f49..dcb4eac1b77952 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -822,6 +822,18 @@ def test_decompress_unused_data(self):
                 self.assertEqual(dco.unconsumed_tail, b'')
                 self.assertEqual(dco.unused_data, remainder)
 
+    def test_decompress_unconsumed_tail_after_eof(self):
+        source = b'abcdefghijklmnopqrstuvwxyz'
+        remainder = b'0123456789'
+        dco = zlib.decompressobj()
+        data = dco.decompress(zlib.compress(source) + remainder, 1)
+        data += dco.decompress(dco.unconsumed_tail)
+
+        self.assertTrue(dco.eof)
+        self.assertEqual(data, source)
+        self.assertEqual(dco.unconsumed_tail, b'')
+        self.assertEqual(dco.unused_data, remainder)
+
     # issue27164
     def test_decompress_raw_with_dictionary(self):
         zdict = b'abcdefghijklmnopqrstuvwxyz'
diff --git a/Misc/NEWS.d/next/Library/2026-09-25-22-15-54.gh-issue-158169.ZlibTail.rst b/Misc/NEWS.d/next/Library/2026-09-25-22-15-54.gh-issue-158169.ZlibTail.rst
new file mode 100644
index 00000000000000..7c965451c056a4
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-09-25-22-15-54.gh-issue-158169.ZlibTail.rst
@@ -0,0 +1,2 @@
+Fix :attr:`zlib.Decompress.unconsumed_tail` duplicating
+:attr:`~zlib.Decompress.unused_data` after end of stream when *max_length* was used.
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index 56c119db7d10c0..31533fa047af0b 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -838,6 +838,7 @@ save_unconsumed_input(compobject *self, Py_buffer *data, int err)
                 return -1;
             }
             Py_SETREF(self->unused_data, new_unused_data);
+            self->zst.next_in += left_size;
             self->zst.avail_in = 0;
         }
     }