diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3e2c7385..f5aadb66 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,6 +39,7 @@ jobs:
       - name: Install Poetry
         uses: snok/install-poetry@v1
         with:
+          version: '1.5.1'
           virtualenvs-in-project: true
       - name: Load cached venv
         id: cached-poetry-dependencies