diff --git a/CHANGELOG.md b/CHANGELOG.md
index d1f538b..6058782 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,14 @@ instructions, because git commits are used to generate release notes:
 
 <!-- scriv-insert-here -->
 
+<a id='changelog-21.0.0'></a>
+## v21.0.0 (2025-10-01)
+
+- [Improvement] Migrate from pylint and black to ruff. (by @mlabeeb03)
+- [Improvement] Test python package distribution build when running make test. (by @mlabeeb03)
+
+- 💥[Feature] Upgrade to Ulmo. (by @mlabeeb03)
+
 <a id='changelog-20.0.0'></a>
 ## v20.0.0 (2025-06-02)
 
diff --git a/changelog.d/20250808_150533_muhammad.labeeb_release.md b/changelog.d/20250808_150533_muhammad.labeeb_release.md
deleted file mode 100644
index 7d482d7..0000000
--- a/changelog.d/20250808_150533_muhammad.labeeb_release.md
+++ /dev/null
@@ -1,2 +0,0 @@
-- [Improvement] Migrate from pylint and black to ruff. (by @mlabeeb03)
-- [Improvement] Test python package distribution build when running make test. (by @mlabeeb03)
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index 2149e59..5c52538 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",
   "quart",
   "aiofiles",
   "markdown",
@@ -39,7 +39,7 @@ dynamic = ["version"]
 
 [project.optional-dependencies]
 dev = [
-  "tutor[dev]>=20.0.0,<21.0.0",
+  "tutor[dev]>=21.0.0,<22.0.0",
   "types-aiofiles",
   "types-Markdown",
   "ruff", 
diff --git a/tutordeck/__about__.py b/tutordeck/__about__.py
index 7c2c079..9bfcca5 100644
--- a/tutordeck/__about__.py
+++ b/tutordeck/__about__.py
@@ -1 +1 @@
-__version__ = "20.1.0"
+__version__ = "21.0.0"