diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 07e4401..b80428c 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -62,7 +62,7 @@ jobs:
             extra-deps: "'virtualenv<20.22.0'"
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
           # >= 3.11 to ensure there's a recent one to run nox with
           # (assumption: last one listed ends up as "python3")
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 9f7925c..d4d87aa 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -26,7 +26,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           ref: ${{ needs.release_please.outputs.sha }}
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
           python-version: "3.10"
       - name: Create release assets