diff --git a/.github/workflows/documentation.yaml b/.github/workflows/documentation.yaml
index 95911cc..99177fb 100644
--- a/.github/workflows/documentation.yaml
+++ b/.github/workflows/documentation.yaml
@@ -5,7 +5,7 @@ jobs:
   docs:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       with:
         ref: ${{ github.event.pull_request.head.ref }}
 
diff --git a/.github/workflows/terraform_fmt.yaml b/.github/workflows/terraform_fmt.yaml
index 348980e..c6499dc 100644
--- a/.github/workflows/terraform_fmt.yaml
+++ b/.github/workflows/terraform_fmt.yaml
@@ -9,7 +9,7 @@ jobs:
     name: Check if terraform files are formatted correctly.
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
         with:
           ref: ${{ github.event.pull_request.head.ref }}