diff --git a/.github/workflows/documentation.yml b/.github/workflows/documentation.yml
index b93eaa575..7acd9dc96 100644
--- a/.github/workflows/documentation.yml
+++ b/.github/workflows/documentation.yml
@@ -11,7 +11,7 @@ jobs:
     if: "!contains(github.event.head_commit.message, '#skip_ci')"
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
       with:
         persist-credentials: false 
         fetch-depth: 0
diff --git a/.github/workflows/dotnet-core-samples.yml b/.github/workflows/dotnet-core-samples.yml
index 529111065..70b9b9491 100644
--- a/.github/workflows/dotnet-core-samples.yml
+++ b/.github/workflows/dotnet-core-samples.yml
@@ -13,7 +13,7 @@ jobs:
     if: "!contains(github.event.head_commit.message, '#skip_ci')"
      
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
     - name: Fetch
       run: git fetch --unshallow
     - name: Setup .NET Core
diff --git a/.github/workflows/dotnet-core-tests.yml b/.github/workflows/dotnet-core-tests.yml
index abaafd01f..fed8643fe 100644
--- a/.github/workflows/dotnet-core-tests.yml
+++ b/.github/workflows/dotnet-core-tests.yml
@@ -13,7 +13,7 @@ jobs:
     if: "!contains(github.event.head_commit.message, '#skip_ci')"
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
     - name: Fetch
       run: git fetch --unshallow
     - name: Setup .NET Core
diff --git a/.github/workflows/dotnet-core.yml b/.github/workflows/dotnet-core.yml
index 3da18e941..20a75479c 100644
--- a/.github/workflows/dotnet-core.yml
+++ b/.github/workflows/dotnet-core.yml
@@ -17,7 +17,7 @@ jobs:
         os: [ubuntu-16.04, windows-latest, macos-latest]
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
     - name: Fetch
       run: git fetch --unshallow
     - name: Setup .NET Core
diff --git a/.github/workflows/nuget-package.yml b/.github/workflows/nuget-package.yml
index 6277b37e8..3dd91b3ca 100644
--- a/.github/workflows/nuget-package.yml
+++ b/.github/workflows/nuget-package.yml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
     - name: Fetch
       run: git fetch --unshallow
     - name: Setup .NET Core