diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d1efb9a53..4aeaac915 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -16,7 +16,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - uses: technote-space/get-diff-action@v4.1.1
         id: git_diff
         with:
diff --git a/.github/workflows/deploy-contract.yml b/.github/workflows/deploy-contract.yml
index ee77ceb56..b06a6ea78 100644
--- a/.github/workflows/deploy-contract.yml
+++ b/.github/workflows/deploy-contract.yml
@@ -16,7 +16,7 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - name: Use Node.js
         uses: actions/setup-node@v2.1.5
         with:
diff --git a/.github/workflows/linkchecker.yml b/.github/workflows/linkchecker.yml
index 44c94b1a3..3655c8de6 100644
--- a/.github/workflows/linkchecker.yml
+++ b/.github/workflows/linkchecker.yml
@@ -6,7 +6,7 @@ jobs:
   markdown-link-check:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@development
+      - uses: actions/checkout@v2.3.4
       - uses: gaurav-nelson/github-action-markdown-link-check@1.0.12
         with:
           folder-path: "docs"
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 4c1923564..c718c838a 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - uses: technote-space/get-diff-action@v4.1.1
         with:
           SUFFIX_FILTER: |
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d1d104f8a..abced7276 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
           go-version: 1.15
@@ -30,7 +30,7 @@ jobs:
   split-test-files:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - name: Create a file with all the pkgs
         run: go list ./... | grep -Ev 'vendor|importer|rpc/tester' > pkgs.txt
       - name: Split pkgs into 4 files
@@ -58,7 +58,7 @@ jobs:
     needs: split-test-files
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
           go-version: 1.15
@@ -97,7 +97,7 @@ jobs:
     needs: split-test-files
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
           go-version: 1.15
@@ -136,7 +136,7 @@ jobs:
     needs: split-test-files
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
           go-version: 1.15
@@ -175,7 +175,7 @@ jobs:
     needs: split-test-files
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
           go-version: 1.15
@@ -213,7 +213,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - uses: actions/setup-go@v2.1.3
         with:
           go-version: 1.15
@@ -233,7 +233,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
       - uses: technote-space/get-diff-action@v4.1.1
         id: git_diff
         with: