diff --git a/.github/workflows/composer-normalize.yml b/.github/workflows/composer-normalize.yml
index 2db8ab3..553e1bb 100644
--- a/.github/workflows/composer-normalize.yml
+++ b/.github/workflows/composer-normalize.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Git checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
 
       - name: Validate Composer configuration
         run: composer validate --strict
diff --git a/.github/workflows/markdown-normalize.yml b/.github/workflows/markdown-normalize.yml
index 4d6bb70..cc1c37f 100644
--- a/.github/workflows/markdown-normalize.yml
+++ b/.github/workflows/markdown-normalize.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Git checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
 
       - name: Prettify markdown
         uses: creyD/prettier_action@v3.3