diff --git a/.github/workflows/build-docs.yml b/.github/workflows/build-docs.yml
index 2d197a7e..2b445210 100644
--- a/.github/workflows/build-docs.yml
+++ b/.github/workflows/build-docs.yml
@@ -25,7 +25,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
 
       - name: Cache Bazel Unix
-        uses: actions/cache@v2.1.5
+        uses: actions/cache@v4
         with:
           path: |
             ./bazel-PyDP
@@ -63,7 +63,7 @@ jobs:
           echo "::set-output name=dir::$(poetry config cache-dir)"
 
       - name: poetry cache
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: ${{ steps.poetry-cache.outputs.dir }}
           key: ${{ runner.os }}-pip-py${{ matrix.python-version }}-${{ hashFiles('**/pyproject.toml') }}
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 75aafd30..e7d15cfb 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -37,7 +37,7 @@ jobs:
       - name: Cache Bazel Unix
         # Not working on Windows: https://github.com/actions/cache/issues/576
         if: runner.os != 'Windows'
-        uses: actions/cache@v2.1.5
+        uses: actions/cache@v4
         with:
           path: |
             ./bazel-PyDP
@@ -56,7 +56,7 @@ jobs:
       - name: Cache Bazel Windows
         if: runner.os == 'Windows'
         # https://stackoverflow.com/questions/66870002/github-actions-cache-maven-m2-repository-on-windows-environment-c-users-run
-        uses: actions/cache@v2.1.5
+        uses: actions/cache@v4
         with:
           path: |
             ./bazel-cache
@@ -128,7 +128,7 @@ jobs:
           echo "::set-output name=dir::$(poetry config cache-dir)"
 
       - name: poetry cache
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: ${{ steps.poetry-cache.outputs.dir }}
           key: ${{ runner.os }}-pip-py${{ matrix.python-version }}-${{ hashFiles('**/pyproject.toml') }}
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 16aff038..b0f17ee4 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -80,7 +80,7 @@ jobs:
       - name: Cache Bazel Unix
         # Not working on Windows: https://github.com/actions/cache/issues/576
         if: runner.os != 'Windows'
-        uses: actions/cache@v2.1.5
+        uses: actions/cache@v4
         with:
           path: |
             ./bazel-PyDP
@@ -99,7 +99,7 @@ jobs:
       - name: Cache Bazel Windows
         if: runner.os == 'Windows'
         # https://stackoverflow.com/questions/66870002/github-actions-cache-maven-m2-repository-on-windows-environment-c-users-run
-        uses: actions/cache@v2.1.5
+        uses: actions/cache@v4
         with:
           path: |
             ./bazel-cache
@@ -146,7 +146,7 @@ jobs:
           echo "::set-output name=dir::$(poetry config cache-dir)"
 
       - name: poetry cache
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: ${{ steps.poetry-cache.outputs.dir }}
           key: ${{ runner.os }}-pip-py${{ matrix.python-version }}-${{ hashFiles('**/pyproject.toml') }}
diff --git a/.github/workflows/versions.yml b/.github/workflows/versions.yml
index 0689b185..7570bcbe 100644
--- a/.github/workflows/versions.yml
+++ b/.github/workflows/versions.yml
@@ -78,7 +78,7 @@ jobs:
       - name: Cache Bazel Unix
         # Not working on Windows: https://github.com/actions/cache/issues/576
         if: runner.os != 'Windows'
-        uses: actions/cache@v2.1.5
+        uses: actions/cache@v4
         with:
           path: |
             ./bazel-PyDP
@@ -97,7 +97,7 @@ jobs:
       - name: Cache Bazel Windows
         if: runner.os == 'Windows'
         # https://stackoverflow.com/questions/66870002/github-actions-cache-maven-m2-repository-on-windows-environment-c-users-run
-        uses: actions/cache@v2.1.5
+        uses: actions/cache@v4
         with:
           path: |
             ./bazel-cache
@@ -144,7 +144,7 @@ jobs:
           echo "::set-output name=dir::$(poetry config cache-dir)"
 
       - name: poetry cache
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: ${{ steps.poetry-cache.outputs.dir }}
           key: ${{ runner.os }}-pip-py${{ matrix.python-version }}-${{ hashFiles('**/pyproject.toml') }}