diff --git a/ignore-utf16.patch b/ignore-utf16.patch
new file mode 100644
index 0000000..f87c3a0
--- /dev/null
+++ b/ignore-utf16.patch
@@ -0,0 +1,32 @@
+From 412479e5d6b02f7dd7e20f870132a413dc83898a Mon Sep 17 00:00:00 2001
+From: Doyle Rowland <doyle.rowland@reliaqual.com>
+Date: Thu, 14 Aug 2025 17:58:02 -0400
+Subject: [PATCH] fix: explicitly ignore utf_16 and utf_32 encoding
+
+---
+ src/docformatter/encode.py | 12 +++++++++---
+ 1 file changed, 9 insertions(+), 3 deletions(-)
+
+diff --git a/src/docformatter/encode.py b/src/docformatter/encode.py
+index ac55ee9..c7e36f0 100644
+--- a/src/docformatter/encode.py
++++ b/src/docformatter/encode.py
+@@ -64,9 +64,15 @@ def do_detect_encoding(self, filename) -> None:
+         """
+         try:
+             detection_result = from_path(filename).best()
+-            self.encoding = (
+-                detection_result.encoding if detection_result else self.DEFAULT_ENCODING
+-            )
++            if detection_result and detection_result.encoding in ["utf_16", "utf_32"]:
++                # Treat undetectable/binary encodings as failure
++                self.encoding = self.DEFAULT_ENCODING
++            else:
++                self.encoding = (
++                    detection_result.encoding
++                    if detection_result
++                    else self.DEFAULT_ENCODING
++                )
+ 
+             # Check for correctness of encoding.
+             with self.do_open_with_encoding(filename) as check_file:
diff --git a/python-docformatter.changes b/python-docformatter.changes
index 2350d7b..29ee10b 100644
--- a/python-docformatter.changes
+++ b/python-docformatter.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Fri Nov 14 13:51:14 UTC 2025 - Markéta Machová <mmachova@suse.com>
+
+- Add upstream ignore-utf16.patch to fix test failure
+
 -------------------------------------------------------------------
 Mon May 19 10:01:24 UTC 2025 - John Paul Adrian Glaubitz <adrian.glaubitz@suse.com>
 
diff --git a/python-docformatter.spec b/python-docformatter.spec
index 3c2350e..4cfe21e 100644
--- a/python-docformatter.spec
+++ b/python-docformatter.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package python-docformatter
 #
-# Copyright (c) 2025 SUSE LLC
+# Copyright (c) 2025 SUSE LLC and contributors
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -26,6 +26,8 @@ URL:            https://github.com/myint/docformatter
 Source:         https://github.com/PyCQA/docformatter/archive/refs/tags/v%{version}.tar.gz#/docformatter-%{version}.tar.gz
 # PATCH-FIX-OPENSUSE Do not require virtualenvs to run the tests
 Patch0:         do-not-require-venv.patch
+# PATCH-FIX-UPSTREAM cherry-pick from https://github.com/PyCQA/docformatter/pull/323 fix: issue 321
+Patch1:         ignore-utf16.patch
 BuildRequires:  %{python_module base >= 3.7}
 BuildRequires:  %{python_module pip}
 BuildRequires:  %{python_module poetry-core}