diff --git a/.github/workflows/after_commit.yml b/.github/workflows/after_commit.yml
index 14a213d..1767d02 100644
--- a/.github/workflows/after_commit.yml
+++ b/.github/workflows/after_commit.yml
@@ -32,7 +32,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Post text to a Slack channel
-        uses: slackapi/slack-github-action@0d95c9a7becc1e6e297d76df9bc735c44f4cbcbc # v3.0.5
+        uses: slackapi/slack-github-action@dcb1066f776dd043e64d0e8ba94ca15cc7e1875d # v4.0.0
         with:
           method: chat.postMessage
           token: ${{ secrets.SLACK_OAUTH_TOKEN }}
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4f190ef..9e6ed1f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -40,7 +40,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Post text to a Slack channel
-        uses: slackapi/slack-github-action@0d95c9a7becc1e6e297d76df9bc735c44f4cbcbc # v3.0.5
+        uses: slackapi/slack-github-action@dcb1066f776dd043e64d0e8ba94ca15cc7e1875d # v4.0.0
         with:
           method: chat.postMessage
           token: ${{ secrets.SLACK_OAUTH_TOKEN }}
diff --git a/.github/workflows/pr_create.yml b/.github/workflows/pr_create.yml
index 7dad97d..0564fa5 100644
--- a/.github/workflows/pr_create.yml
+++ b/.github/workflows/pr_create.yml
@@ -39,7 +39,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Post text to a Slack channel
-        uses: slackapi/slack-github-action@0d95c9a7becc1e6e297d76df9bc735c44f4cbcbc # v3.0.5
+        uses: slackapi/slack-github-action@dcb1066f776dd043e64d0e8ba94ca15cc7e1875d # v4.0.0
         with:
           method: chat.postMessage
           token: ${{ secrets.SLACK_OAUTH_TOKEN }}