diff --git a/CHANGELOG.md b/CHANGELOG.md
index 404bb7a..fb640b5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,14 @@ instructions, because git commits are used to generate release notes:
 
 <!-- scriv-insert-here -->
 
+<a id='changelog-21.0.0'></a>
+## v21.0.0 (2025-10-30)
+
+- [Improvement] Migrate from pylint and black to ruff. (by @rehmansheikh222)
+- [Improvement] Test python package distribution build when running make test. (by @rehmansheikh222)
+
+- 💥[Feature] Upgrade to Ulmo. (by @jfavellar90)
+
 <a id='changelog-20.0.0'></a>
 ## v20.0.0 (2025-06-05)
 
diff --git a/README.rst b/README.rst
index dcb0db0..f78d4de 100644
--- a/README.rst
+++ b/README.rst
@@ -56,7 +56,7 @@ For a problem that includes a file submission, write instead::
 
 Note that in all cases, the queue name must be "openedx".
 
-Save and publish the created unit. Then, access the unit from the LMS and attempt to answer the problem. The answer is sent to the Xqueue service. If you know how to use the Xqueue API, you can access it at http(s)://xqueue.LMS_HOST (in production) or http://xqueue.local.openedx.io (in development). However, the Xqueue API is a bit awkward to use. Tutor provides a simple command-line interface to interact with the Xqueue service.
+Save and publish the created unit. Then, access the unit from the LMS and attempt to answer the problem. The answer is sent to the Xqueue service. If you know how to use the Xqueue API, you can access it at http(s)://xqueue.LMS_HOST (in production) or http://xqueue.www.myopenedx.com (in development). However, the Xqueue API is a bit awkward to use. Tutor provides a simple command-line interface to interact with the Xqueue service.
 
 Count the number of submissions that need to be graded::
 
diff --git a/changelog.d/20250806_163740_abdul.rehman02_migrate_ruff.md b/changelog.d/20250806_163740_abdul.rehman02_migrate_ruff.md
deleted file mode 100644
index 771d1a6..0000000
--- a/changelog.d/20250806_163740_abdul.rehman02_migrate_ruff.md
+++ /dev/null
@@ -1,2 +0,0 @@
-- [Improvement] Migrate from pylint and black to ruff. (by @rehmansheikh222)
-- [Improvement] Test python package distribution build when running make test. (by @rehmansheikh222)
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index b6a7542..25a0d1b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -27,7 +27,7 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
 ]
 dependencies = [
-  "tutor>=20.0.0,<21.0.0",
+  "tutor>=21.0.0,<22.0.0",
 ]
 
 # These fields will be set by hatch_build.py
@@ -35,7 +35,7 @@ dynamic = ["version"]
 
 [project.optional-dependencies]
 dev = [
-    "tutor[dev]>=20.0.0,<21.0.0",
+    "tutor[dev]>=21.0.0,<22.0.0",
     "ruff"
 ]
 
diff --git a/tutorxqueue/__about__.py b/tutorxqueue/__about__.py
index 9c9eb91..9bfcca5 100644
--- a/tutorxqueue/__about__.py
+++ b/tutorxqueue/__about__.py
@@ -1 +1 @@
-__version__ = "20.0.0"
+__version__ = "21.0.0"
diff --git a/tutorxqueue/templates/xqueue/build/xqueue/Dockerfile b/tutorxqueue/templates/xqueue/build/xqueue/Dockerfile
index c5d77e9..ebdbdcd 100644
--- a/tutorxqueue/templates/xqueue/build/xqueue/Dockerfile
+++ b/tutorxqueue/templates/xqueue/build/xqueue/Dockerfile
@@ -34,9 +34,9 @@ ENV PATH=/openedx/venv/bin:${PATH}
 # https://pypi.org/project/setuptools/
 # https://pypi.org/project/pip/
 # https://pypi.org/project/wheel/
-RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared pip install setuptools==78.1.0 pip==25.0.1 wheel==0.46.0
+RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared pip install setuptools==80.9.0 pip==25.3 wheel==0.46.1
 RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared pip install -r requirements.txt
-RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared pip install uwsgi==2.0.28
+RUN --mount=type=cache,target=/openedx/.cache/pip,sharing=shared pip install uwsgi==2.0.31
 
 RUN mkdir /openedx/data /openedx/data/media