diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a6068f8a..ac8b53a59 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## [Unreleased]
 
+- Stopped using `--with-system-expat` when compiling new Python versions. ([#1925](https://github.com/heroku/heroku-buildpack-python/pull/1925))
 
 ## [v312] - 2025-10-05
 
diff --git a/builds/Dockerfile b/builds/Dockerfile
index 8e83a738a..e9f0703fc 100644
--- a/builds/Dockerfile
+++ b/builds/Dockerfile
@@ -17,4 +17,4 @@ RUN apt-get update --error-on=any \
 COPY --from=cosign /ko-app/cosign /usr/local/bin/cosign
 
 WORKDIR /tmp
-COPY build_python_runtime.sh python-3.13-ubuntu-22.04-libexpat-workaround.patch .
+COPY build_python_runtime.sh .
diff --git a/builds/build_python_runtime.sh b/builds/build_python_runtime.sh
index 18a8dc5ea..f78e72b35 100755
--- a/builds/build_python_runtime.sh
+++ b/builds/build_python_runtime.sh
@@ -83,14 +83,6 @@ cosign verify-blob \
 tar --extract --file python.tgz --strip-components=1 --directory "${SRC_DIR}"
 cd "${SRC_DIR}"
 
-# Work around PGO profile test failures with Python 3.13 on Ubuntu 22.04, due to the tests
-# checking the raw libexpat version which doesn't account for Ubuntu backports:
-# https://github.com/heroku/heroku-buildpack-python/pull/1661#issuecomment-2405259352
-# https://github.com/python/cpython/issues/125067
-if [[ "${PYTHON_MAJOR_VERSION}" == "3.13" && "${STACK}" == "heroku-22" ]]; then
-	patch -p1 </tmp/python-3.13-ubuntu-22.04-libexpat-workaround.patch
-fi
-
 # Aim to keep this roughly consistent with the options used in the Python Docker images,
 # for maximum compatibility / most battle-tested build configuration:
 # https://github.com/docker-library/python
@@ -110,9 +102,6 @@ CONFIGURE_OPTS=(
 	# Skip running `ensurepip` as part of install, since the buildpack installs a curated
 	# version of pip itself (which ensures it's consistent across Python patch releases).
 	"--with-ensurepip=no"
-	# Build the `pyexpat` module using the `expat` library in the base image (which will
-	# automatically receive security updates), rather than CPython's vendored version.
-	"--with-system-expat"
 )
 
 if [[ "${PYTHON_MAJOR_VERSION}" != +(3.9) ]]; then
diff --git a/builds/python-3.13-ubuntu-22.04-libexpat-workaround.patch b/builds/python-3.13-ubuntu-22.04-libexpat-workaround.patch
deleted file mode 100644
index fb5676865..000000000
--- a/builds/python-3.13-ubuntu-22.04-libexpat-workaround.patch
+++ /dev/null
@@ -1,24 +0,0 @@
-diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
-index ebec9d8f18a..385735c1e18 100644
---- a/Lib/test/test_xml_etree.py
-+++ b/Lib/test/test_xml_etree.py
-@@ -1504,9 +1504,11 @@ def test_simple_xml(self, chunk_size=None, flush=False):
-         self.assert_event_tags(parser, [('end', 'root')])
-         self.assertIsNone(parser.close())
- 
-+    @unittest.skip('Work around: https://github.com/python/cpython/issues/125067')
-     def test_simple_xml_chunk_1(self):
-         self.test_simple_xml(chunk_size=1, flush=True)
- 
-+    @unittest.skip('Work around: https://github.com/python/cpython/issues/125067')
-     def test_simple_xml_chunk_5(self):
-         self.test_simple_xml(chunk_size=5, flush=True)
- 
-@@ -1731,6 +1733,7 @@ def test_flush_reparse_deferral_enabled(self):
- 
-         self.assert_event_tags(parser, [('end', 'doc')])
- 
-+    @unittest.skip('Work around: https://github.com/python/cpython/issues/125067')
-     def test_flush_reparse_deferral_disabled(self):
-         parser = ET.XMLPullParser(events=('start', 'end'))
-