diff --git a/.github/workflows/assign.yaml b/.github/workflows/assign.yaml
index cd2a71e9575..d072c255803 100644
--- a/.github/workflows/assign.yaml
+++ b/.github/workflows/assign.yaml
@@ -31,7 +31,9 @@ jobs:
       # Checkout master branch of Teleport repository. This is to prevent an
       # attacker from submitting their own review assignment logic.
       - name: Checkout master branch
-        uses: actions/checkout@master        
+        uses: actions/checkout@v2    
+        with:
+          ref: master    
       - name: Installing the latest version of Go.
         uses: actions/setup-go@v2
       # Run "assign-reviewers" subcommand on bot.
diff --git a/.github/workflows/check.yaml b/.github/workflows/check.yaml
index bbc95fa4c60..23dacf70b37 100644
--- a/.github/workflows/check.yaml
+++ b/.github/workflows/check.yaml
@@ -34,7 +34,9 @@ jobs:
       # Checkout master branch of Teleport repository. This is to prevent an
       # attacker from submitting their own review assignment logic. 
       - name: Checkout master branch 
-        uses: actions/checkout@master
+        uses: actions/checkout@v2
+        with:
+          ref: master 
       - name: Installing the latest version of Go.
         uses: actions/setup-go@v2
         # Run "check-reviewers" subcommand on bot.
diff --git a/.github/workflows/dismiss.yaml b/.github/workflows/dismiss.yaml
index 944be6ea2ca..6dc977cedbd 100644
--- a/.github/workflows/dismiss.yaml
+++ b/.github/workflows/dismiss.yaml
@@ -33,7 +33,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout master branch 
-        uses: actions/checkout@master
+        uses: actions/checkout@v2
+        with:
+          ref: master 
       - name: Installing the latest version of Go.
         uses: actions/setup-go@v2
         # Run "dismiss-runs" subcommand on bot.