diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index ce37d87..d348dfb 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -11,7 +11,7 @@ env:
 jobs:
   lint_dockerfile:
     runs-on: ubuntu-latest
-    container: hadolint/hadolint:latest-debian
+    container: hadolint/hadolint:latest-debian@sha256:9a3944b7fddcb947d1ffd90829ac1a6e5c30479223358f249d8b96c7d0019e27
     steps:
       - name: Checkout
         uses: actions/checkout@v2
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 15e4766..e2dbd47 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -5,7 +5,7 @@ on: pull_request
 jobs:
   lint_dockerfile:
     runs-on: ubuntu-latest
-    container: hadolint/hadolint:latest-debian
+    container: hadolint/hadolint:latest-debian@sha256:9a3944b7fddcb947d1ffd90829ac1a6e5c30479223358f249d8b96c7d0019e27
     steps:
       - name: Checkout
         uses: actions/checkout@v2