diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 25070f5..e393d9f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,10 +22,10 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@fbc6f3992d24b796d5a048ff273f7fcc4a7b6c09 # v5
 
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6
         with:
           python-version: "3.11"
           cache: "pip"
diff --git a/.github/workflows/update-star-history.yml b/.github/workflows/update-star-history.yml
index c138384..c6609b7 100644
--- a/.github/workflows/update-star-history.yml
+++ b/.github/workflows/update-star-history.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@fbc6f3992d24b796d5a048ff273f7fcc4a7b6c09 # v5
 
       - name: Generate static star history
         run: python3 scripts/generate_star_history.py
diff --git a/tests/test_common.py b/tests/test_common.py
index 7880b5e..f5a418d 100644
--- a/tests/test_common.py
+++ b/tests/test_common.py
@@ -988,15 +988,15 @@ def test_domain_rules_missing_or_invalid_falls_back(tmp_path: Path, monkeypatch)
 def test_env_config_value_falls_back_to_shell_file(tmp_path: Path, monkeypatch) -> None:
     shell_file = tmp_path / ".zshenv"
     shell_file.write_text(
-        '\n# comment\nexport DEEPPAPERNOTE_SEMANTIC_SCHOLAR_API_KEY="file_based_key"\n',
+        '\n# comment\nexport DEEPPAPERNOTE_SEMANTIC_SCHOLAR_API_KEY="redacted"\n',
         encoding="utf-8",
     )
     monkeypatch.delenv("DEEPPAPERNOTE_SEMANTIC_SCHOLAR_API_KEY", raising=False)
     monkeypatch.delenv("SEMANTIC_SCHOLAR_API_KEY", raising=False)
     monkeypatch.setattr("common.SHELL_CONFIG_FILES", [shell_file])
 
-    assert env_config_value("DEEPPAPERNOTE_SEMANTIC_SCHOLAR_API_KEY") == "file_based_key"
-    assert semantic_scholar_headers()["x-api-key"] == "file_based_key"
+    assert env_config_value("DEEPPAPERNOTE_SEMANTIC_SCHOLAR_API_KEY") == "redacted"
+    assert semantic_scholar_headers()["x-api-key"] == "redacted"
 
 
 def test_check_environment_reports_semantic_scholar_key_from_env(tmp_path: Path) -> None: