diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3196f88..aa04107 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,7 +17,7 @@ jobs:
         python-version: [3.6, 3.7, 3.8, 3.9]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v2
         with:
@@ -53,7 +53,7 @@ jobs:
     if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
 
     steps:
-      - uses: actions/checkout@master
+      - uses: actions/checkout@v3
       - name: Set up Python 3.8
         uses: actions/setup-python@v1
         with:
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 728d7ad..ee85843 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -39,7 +39,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
diff --git a/.github/workflows/latest-changes.yml b/.github/workflows/latest-changes.yml
index 46bb848..f25c48d 100644
--- a/.github/workflows/latest-changes.yml
+++ b/.github/workflows/latest-changes.yml
@@ -16,7 +16,7 @@ jobs:
   latest-changes:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Dump GitHub context
         env:
           GITHUB_CONTEXT: ${{ toJson(github) }}
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index f965299..782ccd5 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -12,7 +12,7 @@ jobs:
         python-version: [3.6, 3.7, 3.8, 3.9]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v2
         with:
@@ -41,7 +41,7 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-      - uses: actions/checkout@master
+      - uses: actions/checkout@v3
       - name: Set up Python 3.8
         uses: actions/setup-python@v1
         with:
diff --git a/.github/workflows/serve-docs.yml b/.github/workflows/serve-docs.yml
index 54b84cc..3ecf0c4 100644
--- a/.github/workflows/serve-docs.yml
+++ b/.github/workflows/serve-docs.yml
@@ -12,7 +12,7 @@ jobs:
         run: |
             echo "PYTHONPATH=/home/runner/work/py2k/py2k" >> $GITHUB_ENV
             echo "/home/runner/work/py2k/py2k/py2k" >> $GITHUB_PATH
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions/setup-python@v2
         with:
           python-version: 3.6