diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9ce314759..01bd83d90 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 - Changed the default Python version for new apps from 3.12 to 3.13. ([#1715](https://github.com/heroku/heroku-buildpack-python/pull/1715))
 - Changed Python version pinning behaviour for apps that do not specify a Python version. Repeat builds are now pinned to the major Python version only (`3.X`) instead of the full Python version (`3.X.Y`), so that they always use the latest patch version. ([#1714](https://github.com/heroku/heroku-buildpack-python/pull/1714))
+- Updated Poetry from 1.8.4 to 1.8.5. ([#1716](https://github.com/heroku/heroku-buildpack-python/pull/1716))
 
 ## [v269] - 2024-12-04
 
diff --git a/requirements/poetry.txt b/requirements/poetry.txt
index 8e44691cb..b7c67421a 100644
--- a/requirements/poetry.txt
+++ b/requirements/poetry.txt
@@ -1 +1 @@
-poetry==1.8.4
+poetry==1.8.5
diff --git a/spec/hatchet/poetry_spec.rb b/spec/hatchet/poetry_spec.rb
index c4514019d..6d3786bd8 100644
--- a/spec/hatchet/poetry_spec.rb
+++ b/spec/hatchet/poetry_spec.rb
@@ -61,8 +61,6 @@
     end
   end
 
-  # TODO: Make this also test the Poetry version changing, the next (first) time we update Poetry,
-  # by using an older buildpack version for the initial build.
   context 'when the requested Python version has changed since the last build' do
     let(:buildpacks) { ['https://github.com/heroku/heroku-buildpack-python#v268'] }
     let(:app) { Hatchet::Runner.new('spec/fixtures/poetry_basic', buildpacks:) }
@@ -77,6 +75,7 @@
           remote: -----> Using Python 3.13 specified in .python-version
           remote: -----> Discarding cache since:
           remote:        - The Python version has changed from 3.13.0 to #{LATEST_PYTHON_3_13}
+          remote:        - The Poetry version has changed from 1.8.4 to #{POETRY_VERSION}
           remote: -----> Installing Python #{LATEST_PYTHON_3_13}
           remote: -----> Installing Poetry #{POETRY_VERSION}
           remote: -----> Installing dependencies using 'poetry install --sync --only main'