diff --git a/.github/workflows/build_and_publish.yml b/.github/workflows/build_and_publish.yml
index 98d8ff8..15b4c01 100644
--- a/.github/workflows/build_and_publish.yml
+++ b/.github/workflows/build_and_publish.yml
@@ -43,7 +43,7 @@ jobs:
     if: needs.tag-new-version.outputs.new_version
     steps:
       - uses: actions/checkout@v6
-      - uses: opensafely-core/setup-action@v1
+      - uses: opensafely-core/setup-action@v1.6.1
         with:
           install-just: true
       - name: Set VERSION environment variable
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 9a9a171..f53faa5 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v6
-      - uses: "opensafely-core/setup-action@v1"
+      - uses: "opensafely-core/setup-action@v1.6.1"
         with:
           install-just: true
           install-uv: true
@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v6
-      - uses: "opensafely-core/setup-action@v1"
+      - uses: "opensafely-core/setup-action@v1.6.1"
         with:
           install-just: true
           install-uv: true
diff --git a/.github/workflows/update-dependencies.yml b/.github/workflows/update-dependencies.yml
index ea2821f..3a986d3 100644
--- a/.github/workflows/update-dependencies.yml
+++ b/.github/workflows/update-dependencies.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
     - uses: actions/checkout@v6
-    - uses: "opensafely-core/setup-action@v1"
+    - uses: "opensafely-core/setup-action@v1.6.1"
       with:
         install-uv: true
         install-just: true
diff --git a/.github/workflows/uvmirror-check.yml b/.github/workflows/uvmirror-check.yml
index 62d29df..0883de8 100644
--- a/.github/workflows/uvmirror-check.yml
+++ b/.github/workflows/uvmirror-check.yml
@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v6
-      - uses: opensafely-core/setup-action@v1
+      - uses: opensafely-core/setup-action@v1.6.1
         with:
           install-just: true
           install-uv: true