diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1817214..6694cc9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
       
     - name: Build the test Docker image
       run: docker build --tag wait-for .
@@ -26,7 +26,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
 
       - name: Setup Node.js
         uses: actions/setup-node@v2.1.5