diff --git a/.github/workflows/test_action.yml b/.github/workflows/test_action.yml
index 66c11ff..ac7ffc4 100644
--- a/.github/workflows/test_action.yml
+++ b/.github/workflows/test_action.yml
@@ -9,9 +9,9 @@ jobs:
     name: Test action
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683  # v4.2.2
       - id: build
-        uses: OpenAstronomy/build-python-dist@v1
+        uses: OpenAstronomy/build-python-dist@bbb0e1c5b132893999ea56d77bd4b526e0097c7d  # v1.0.1
         with:
           pure_python_wheel: true
       - id: upload
@@ -25,9 +25,9 @@ jobs:
     name: Test action (no keep option specified)
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683  # v4.2.2
       - id: build
-        uses: OpenAstronomy/build-python-dist@v1
+        uses: OpenAstronomy/build-python-dist@bbb0e1c5b132893999ea56d77bd4b526e0097c7d  # v1.0.1
         with:
           pure_python_wheel: true
       - id: upload