diff --git a/.github/workflows/docker-build.yml b/.github/workflows/docker-build.yml
index 9d55c18..b32a0d0 100644
--- a/.github/workflows/docker-build.yml
+++ b/.github/workflows/docker-build.yml
@@ -11,7 +11,7 @@ jobs:
   cpython-build-docker:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
         with:
           fetch-depth: 0
       - name: Set up QEMU
@@ -52,7 +52,7 @@ jobs:
   pypy-build-docker:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
         with:
           fetch-depth: 0
       - name: Set up QEMU
@@ -93,7 +93,7 @@ jobs:
   nginx-build-docker:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
         with:
           fetch-depth: 0
       - name: Set up QEMU