diff --git a/.woodpecker/build.yml b/.woodpecker/build.yml
index 65ae7d1..318658b 100644
--- a/.woodpecker/build.yml
+++ b/.woodpecker/build.yml
@@ -3,7 +3,7 @@ depends_on:
   - lint
 steps:
   selfhosted_tag:
-    image: plugins/docker
+    image: plugins/docker@sha256:2f157400c2cb7de1b309b0f044f119375108218e54d38e1340e00b9f93abdefb
     settings:
       dockerfile: Dockerfile
       repo: registry.mgrote.net/miniflux-filter
@@ -15,7 +15,7 @@ steps:
         - tag
 
   selfhosted_push:
-    image: plugins/docker
+    image: plugins/docker@sha256:2f157400c2cb7de1b309b0f044f119375108218e54d38e1340e00b9f93abdefb
     settings:
       dockerfile: Dockerfile
       repo: registry.mgrote.net/miniflux-filter
diff --git a/.woodpecker/lint.yml b/.woodpecker/lint.yml
index 94ae16c..21d4ac5 100644
--- a/.woodpecker/lint.yml
+++ b/.woodpecker/lint.yml
@@ -1,7 +1,7 @@
 ---
 steps:
   gitleaks:
-    image: zricethezav/gitleaks:latest
+    image: zricethezav/gitleaks:latest@sha256:6945c62ca019ead32bc337ab0c9fd055e98d82961765d38b7ccccc84dae95d0f
     commands:
       - gitleaks detect --no-git --verbose --source $CI_WORKSPACE
     when:
@@ -9,7 +9,7 @@ steps:
         exclude:
           - tag
   hadolint:
-    image: hadolint/hadolint:latest-debian
+    image: hadolint/hadolint:latest-debian@sha256:9cef74a390694cdc01dd119cbba9adac5bb6671ce67d8d79eb7ec68f497a3684
     commands:
       - hadolint Dockerfile
     when:
diff --git a/Dockerfile b/Dockerfile
index e5fffab..c303d72 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:20231219
+FROM alpine:20231219@sha256:9f867dc20de5aa9690c5ef6c2c81ce35a918c0007f6eac27df90d3166eaa5cc0
 
 # hadolint ignore=DL3018
 RUN apk add --no-cache \
diff --git a/docker-compose.yml b/docker-compose.yml
index c7f4892..b6392bd 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -9,6 +9,6 @@ services:
       - MF_API_URL=https://miniflux.[...].net/v1
       - MF_SLEEP=60
       #- MF_DEBUG=1
-    image: quotengrote/miniflux-filter:latest
+    image: quotengrote/miniflux-filter:latest@sha256:a99744babfb63fa4566db0ed0219fbffe7580d5dae20b2b018a3bdc8d05aa0c5
     volumes:
       - ./filter.txt:/data/filter.txt