diff --git a/.github/workflows/setup.yml b/.github/workflows/setup.yml
index e57cffe88..1859e6fe9 100644
--- a/.github/workflows/setup.yml
+++ b/.github/workflows/setup.yml
@@ -7,13 +7,13 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/cache@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
         with:
           path: ~/.cache/pip
           key: ${{ runner.os }}-pip-setup-${{ hashFiles('**/requirements*.txt') }}
       - name: Setup Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: 3.8
       - name: Install Gammu
@@ -29,7 +29,7 @@ jobs:
       - name: twine
         run: twine check dist/*
       - name: Store the binary wheel
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: python-package-distributions
           path: dist
@@ -47,13 +47,13 @@ jobs:
         architecture: [x64, x86]
 
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/cache@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
         with:
           path: ~/.cache/pip
           key: ${{ runner.os }}-pip-setup-${{ hashFiles('**/requirements*.txt') }}
       - name: Setup Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: ${{ matrix.python-version }}
           architecture: ${{ matrix.architecture }}
@@ -76,7 +76,7 @@ jobs:
       - name: twine
         run: twine check dist/*
       - name: Store the binary wheel
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: python-package-distributions
           path: dist
@@ -88,15 +88,15 @@ jobs:
       - windows
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
       - name: Download all the dists
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4
         with:
           name: python-package-distributions
           path: dist/
       - name: Publish package
         if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags')
-        uses: pypa/gh-action-pypi-publish@v1.12.2
+        uses: pypa/gh-action-pypi-publish@15c56dba361d8335944d31a2ecd17d700fc7bcbc # v1.12.2
         with:
           user: __token__
           password: ${{ secrets.pypi_password }}
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 05e2149a1..89cd113d8 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -17,14 +17,14 @@ jobs:
     name: ${{ matrix.os }}, Python ${{ matrix.python-version }}
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
       - name: Cache pip
-        uses: actions/cache@v4
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
         with:
           path: ~/.cache/pip
           key: ${{ runner.os }}-pip-${{ matrix.python-version }}-${{ hashFiles('**/requirements*.txt') }}
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install gammu
@@ -48,6 +48,6 @@ jobs:
         run: coverage run --source=. ./setup.py test
       - name: Coverage
         run: coverage xml
-      - uses: codecov/codecov-action@v5
+      - uses: codecov/codecov-action@671740ac38dd9b0130fbe1cec585b89eea48d3de # v5
         with:
           name: ${{ matrix.os }}, Python ${{ matrix.python-version }}