diff --git a/.woodpecker/pr.yml b/.woodpecker/pr.yml
index 48f0c64..d221b16 100644
--- a/.woodpecker/pr.yml
+++ b/.woodpecker/pr.yml
@@ -1,7 +1,7 @@
 ---
 pipeline:
   pr-lint:
-    image: alpine/helm
+    image: alpine/helm@sha256:8d7ce0aba587ee956dfa2d0f9a6db8de3e0f68157a99639c26c759d43df4897b
     environment:
       USE_SSH: "true"
       GIT_USER: $DRONE_COMMIT_AUTHOR
diff --git a/.woodpecker/release.yml b/.woodpecker/release.yml
index bc913ef..f40f0ea 100644
--- a/.woodpecker/release.yml
+++ b/.woodpecker/release.yml
@@ -1,7 +1,7 @@
 ---
 pipeline:
   helm-repo:
-    image: quay.io/helmpack/chart-releaser
+    image: quay.io/helmpack/chart-releaser@sha256:3d2a5a586409b9b5411022a0212f09cdebe38698653baddd063f5aa798e9909a
     commands:
     - git config --global user.email "noreply@lib42.github.io"
     - git config --global user.name "Woodpecker-CI"