diff --git a/.github/workflows/pages.yml b/.github/workflows/pages.yml
index 7ad94e1..38a8911 100644
--- a/.github/workflows/pages.yml
+++ b/.github/workflows/pages.yml
@@ -8,7 +8,7 @@ on:
     branches: [main]
 
 env:
-  POETRY_VERSION: "2.2.1"
+  POETRY_VERSION: "2.1.1"
   PYTHON_VERSION: "3.11"
 
 jobs:
diff --git a/.github/workflows/python.yml b/.github/workflows/python.yml
index a8a6c66..f389dd3 100644
--- a/.github/workflows/python.yml
+++ b/.github/workflows/python.yml
@@ -3,7 +3,7 @@ name: python
 on: [push, pull_request]
 
 env:
-  POETRY_VERSION: "2.2.1"
+  POETRY_VERSION: "2.1.1"
   PYTHON_VERSION: "3.11"
 
 jobs:
diff --git a/Dockerfile b/Dockerfile
index aabaf8e..fec8d9f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -11,7 +11,7 @@
 FROM python:3.11-slim-bookworm AS python_builder
 
 # Pin Poetry to a specific version to make Docker builds reproducible.
-ENV POETRY_VERSION=2.2.1
+ENV POETRY_VERSION=2.1.1
 
 # Set ENV variables that make Python more friendly to running inside a container.
 ENV PYTHONDONTWRITEBYTECODE=1