diff --git a/.github/workflows/package.yml b/.github/workflows/package.yml
index d47ddb7..77785c8 100644
--- a/.github/workflows/package.yml
+++ b/.github/workflows/package.yml
@@ -336,14 +336,14 @@ jobs:
 
       - name: Publish to TestPyPI
         if: ${{ github.event_name == 'workflow_dispatch' && inputs.publish_target == 'testpypi' }}
-        uses: pypa/gh-action-pypi-publish@v1.14.2 # v1.14.2 image tag is required by this composite action
+        uses: pypa/gh-action-pypi-publish@7245906fb61fa33a13554f9d5fb856fe61758086 # v1.14.3
         with:
           packages-dir: dist
           repository-url: https://test.pypi.org/legacy/
 
       - name: Publish to PyPI
         if: ${{ (github.event_name == 'push' && github.ref_type == 'tag') || (github.event_name == 'workflow_dispatch' && inputs.publish_target == 'pypi') }}
-        uses: pypa/gh-action-pypi-publish@v1.14.2 # v1.14.2 image tag is required by this composite action
+        uses: pypa/gh-action-pypi-publish@7245906fb61fa33a13554f9d5fb856fe61758086 # v1.14.3
         with:
           packages-dir: dist
 
diff --git a/tests/test_package_workflow.py b/tests/test_package_workflow.py
index 38dd089..959c048 100644
--- a/tests/test_package_workflow.py
+++ b/tests/test_package_workflow.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import re
 from pathlib import Path
 
 import yaml
@@ -24,11 +25,24 @@ def test_package_workflow_can_recover_an_immutable_tag_from_default_branch() ->
     assert '--source-commit "$SOURCE_COMMIT"' in workflow
 
 
-def test_package_workflow_uses_a_published_pypi_publisher_image_tag() -> None:
+def test_package_workflow_uses_the_pinned_pypi_publisher_release() -> None:
     workflow = (Path(__file__).resolve().parents[1] / ".github/workflows/package.yml").read_text(encoding="utf-8")
 
-    assert workflow.count("uses: pypa/gh-action-pypi-publish@v1.14.2") == 2
-    assert "pypa/gh-action-pypi-publish@a892a5a61159132606e93a2fa6f4358831b04d26" not in workflow
+    assert workflow.count("uses: pypa/gh-action-pypi-publish@7245906fb61fa33a13554f9d5fb856fe61758086") == 2
+
+
+def test_all_workflows_pin_every_third_party_action_to_a_full_sha() -> None:
+    workflow_dir = Path(__file__).resolve().parents[1] / ".github/workflows"
+    workflows = sorted(workflow_dir.glob("*.yml"))
+    assert workflows
+
+    unpinned: list[tuple[str, str]] = []
+    for workflow_path in workflows:
+        workflow = workflow_path.read_text(encoding="utf-8")
+        refs = re.findall(r"^\s*-?\s*uses:\s+[^@\s]+@([^\s#]+)", workflow, flags=re.MULTILINE)
+        unpinned.extend((workflow_path.name, ref) for ref in refs if not re.fullmatch(r"[0-9a-f]{40}", ref))
+
+    assert unpinned == []
 
 
 def test_package_workflow_does_not_replace_published_release_assets() -> None: