diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 4cc8153..249c889 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -22,7 +22,7 @@ jobs:
     runs-on: ubuntu-18.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
 
       - name: Cache Docker layers
         uses: actions/cache@v2.1.4