diff --git a/dev-python/testfixtures/files/testfixtures-12.3.0-py3.15.patch b/dev-python/testfixtures/files/testfixtures-12.3.0-py3.15.patch
new file mode 100644
index 0000000000000..387c07ea59897
--- /dev/null
+++ b/dev-python/testfixtures/files/testfixtures-12.3.0-py3.15.patch
@@ -0,0 +1,36 @@
+https://github.com/simplistix/testfixtures/pull/258
+
+From 7c8dce6247d781c8fa8408e4078605df5c231796 Mon Sep 17 00:00:00 2001
+From: Alfred Wingate <parona@protonmail.com>
+Date: Sun, 19 Jul 2026 14:52:17 +0300
+Subject: [PATCH] Fix tests with Python 3.15
+
+See-Also: https://github.com/python/cpython/pull/149298
+Signed-off-by: Alfred Wingate <parona@protonmail.com>
+---
+ tests/test_shouldwarn.py | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/tests/test_shouldwarn.py b/tests/test_shouldwarn.py
+index a1d31b0..e4411f1 100644
+--- a/tests/test_shouldwarn.py
++++ b/tests/test_shouldwarn.py
+@@ -1,5 +1,6 @@
+ from unittest import TestCase
+ 
++import sys
+ import warnings
+ 
+ from testfixtures import (
+@@ -147,6 +148,8 @@ class ShouldWarnTests(TestCase):
+             message=C(DeprecationWarning('foo')),
+             source=None
+         )
++        if sys.version_info >= (3, 15):
++            expected_attrs['module']='bar_module'
+ 
+         compare(expected=C(warnings.WarningMessage, **expected_attrs),
+             actual=recorded[0])
+-- 
+2.55.0
+
diff --git a/dev-python/testfixtures/testfixtures-12.3.0.ebuild b/dev-python/testfixtures/testfixtures-12.3.0.ebuild
index 166f504bce6a0..71efc9a83e8a2 100644
--- a/dev-python/testfixtures/testfixtures-12.3.0.ebuild
+++ b/dev-python/testfixtures/testfixtures-12.3.0.ebuild
@@ -5,7 +5,7 @@ EAPI=8
 
 DISTUTILS_USE_PEP517=hatchling
 PYPI_VERIFY_REPO=https://github.com/simplistix/testfixtures
-PYTHON_COMPAT=( python3_{12..14} )
+PYTHON_COMPAT=( python3_{12..15} )
 
 inherit distutils-r1 pypi
 
@@ -37,6 +37,10 @@ BDEPEND="
 EPYTEST_PLUGINS=( pytest-django )
 distutils_enable_tests pytest
 
+PATCHES=(
+	"${FILESDIR}"/testfixtures-12.3.0-py3.15.patch
+)
+
 python_test() {
 	local -x PYTHONPATH="."
 	local -x DJANGO_SETTINGS_MODULE=tests.test_django.settings