diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6f955d0..e9d81d3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,7 +15,7 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - uses: rlespinasse/github-slug-action@master
+    - uses: rlespinasse/github-slug-action@1.1.1
 
     - name: build and publish auth server Docker container
       uses: elgohr/Publish-Docker-Github-Action@2.14