diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index e01d5ea..98e4e5d 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -22,7 +22,7 @@ jobs:
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
       - name: Base Setup
-        uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
+        uses: jupyterlab/maintainer-tools/.github/actions/base-setup@affc83be6020d529b9368cd4d63e467877606600 # v1
 
       - name: Install JupyterLab
         run: python -m pip install -U "jupyterlab>=4.0.0,<5"