diff --git a/.github/workflows/unit_tests.yml b/.github/workflows/unit_tests.yml
index eced3574..41e51bbe 100644
--- a/.github/workflows/unit_tests.yml
+++ b/.github/workflows/unit_tests.yml
@@ -23,7 +23,7 @@ jobs:
         python-version: ["py310", "py311", "py312"]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - name: Run Test
         id: tests
@@ -59,11 +59,13 @@ jobs:
           echo "BRANCH=${BRANCH#refs/*/}" >> $GITHUB_ENV
 
       - name: Notify if test FAILED
-        uses: archive/github-actions-slack@v2.0.0
+        uses: slackapi/slack-github-action@v3.0.2
         with:
-          slack-bot-user-oauth-access-token: ${{ secrets.SLACK_BOT_TOKEN }}
-          slack-channel: ${{ secrets.SLACK_CHANNEL_ID }}
-          slack-text: ":boom: *${{ env.FAILED_AMOUNT }}* Pycaption test(s) failed for Python *${{ matrix.python-version }}* on the *${{ env.BRANCH }}* branch (triggered by *${{ github.actor }}*)"
+          method: chat.postMessage
+          token: ${{ secrets.SLACK_BOT_TOKEN }}
+          payload: |
+            channel: ${{ secrets.SLACK_CHANNEL_ID }}
+            text: ":boom: *${{ env.FAILED_AMOUNT }}* Pycaption test(s) failed for Python *${{ matrix.python-version }}* on the *${{ env.BRANCH }}* branch (triggered by *${{ github.actor }}*)"
         if: steps.tests.outcome == 'failure' && !github.event.pull_request.head.repo.fork
 
       - name: Mark test failure
@@ -71,9 +73,11 @@ jobs:
         if: steps.tests.outcome == 'failure'
 
       - name: Slack notify tests PASSED
-        uses: archive/github-actions-slack@v2.0.0
+        uses: slackapi/slack-github-action@v3.0.2
         with:
-          slack-bot-user-oauth-access-token: ${{ secrets.SLACK_BOT_TOKEN }}
-          slack-channel: ${{ secrets.SLACK_CHANNEL_ID }}
-          slack-text: ":rocket: All (*${{ env.PASSED_AMOUNT }}*) Pycaption tests passed for Python *${{ matrix.python-version }}* covering *${{ env.COVERAGE }}%* of code on the *${{ env.BRANCH }}* branch (triggered by *${{ github.actor }}*)"
+          method: chat.postMessage
+          token: ${{ secrets.SLACK_BOT_TOKEN }}
+          payload: |
+            channel: ${{ secrets.SLACK_CHANNEL_ID }}
+            text: ":rocket: All (*${{ env.PASSED_AMOUNT }}*) Pycaption tests passed for Python *${{ matrix.python-version }}* covering *${{ env.COVERAGE }}%* of code on the *${{ env.BRANCH }}* branch (triggered by *${{ github.actor }}*)"
         if: steps.tests.outcome == 'success' && !github.event.pull_request.head.repo.fork
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 664d49b8..b9ae457f 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -10,6 +10,10 @@ Changelog
   - Code reformatted with Black/isort across the codebase
   - Added missing tests for _PositioningTracker,
     Alignment.from_horizontal_and_vertical_align
+    - Bump actions/checkout from v2 to v4 in CI workflow
+    - Replace unmaintained archive/github-actions-slack with
+      slackapi/slack-github-action@v3.0.2 (fixes Node.js and
+      set-output deprecation warnings)
 
 2.2.20
 ^^^^^^
diff --git a/setup.py b/setup.py
index 177853bc..8b58ea63 100644
--- a/setup.py
+++ b/setup.py
@@ -20,7 +20,7 @@
 
 setup(
     name="pycaption",
-    version="2.2.21.dev1",
+    version="2.2.21.dev2",
     description="Closed caption converter",
     long_description=open(README_PATH).read(),
     author="Joe Norton",