diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 509de5c..734581a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,15 +14,15 @@ jobs:
   dp-operations-lint:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
       with:
         fetch-depth: 0
-    - uses: tj-actions/changed-files@v46
+    - uses: tj-actions/changed-files@9426d40962ed5378910ee2e21d5f8c6fcbf2dd96 # v47.0.6
       id: changed-files
       with:
         files: '**/*.md'
         separator: ","
-    - uses: DavidAnson/markdownlint-cli2-action@v20
+    - uses: DavidAnson/markdownlint-cli2-action@21c1be1b93ad9ed58fa840aacc3f279cde2a72ff # v24.2.0
       if: steps.changed-files.outputs.any_changed == 'true'
       with:
         globs: ${{ steps.changed-files.outputs.all_changed_files }}