diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index ac7717b..28a2c6a 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -12,7 +12,7 @@ jobs:
         unreleased: ['ON', 'OFF']
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Install
@@ -46,7 +46,7 @@ jobs:
             - {compiler: '11', standard: '20'}
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Install
@@ -78,7 +78,7 @@ jobs:
             - {compiler: 'g++-7', standard: '20'}
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Install
@@ -117,7 +117,7 @@ jobs:
             - {compiler: '9',   standard: '20'}
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Install
@@ -146,7 +146,7 @@ jobs:
 #        unreleased: ['ON', 'OFF']
 #    steps:
 #      - name: Checkout
-#        uses: actions/checkout@v3
+#        uses: actions/checkout@v4
 #        with:
 #          submodules: true
 #      - name: Install
@@ -171,7 +171,7 @@ jobs:
         unreleased: ['ON', 'OFF']
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Install
@@ -198,7 +198,7 @@ jobs:
         unreleased: ['ON', 'OFF']
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Install
@@ -224,7 +224,7 @@ jobs:
         unreleased: ['ON', 'OFF']
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Install