diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 646bd26..2825b64 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -9,10 +9,10 @@ jobs:
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
     - name: Set up Python
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
       with:
         python-version: 3.14
 
diff --git a/Dockerfile b/Dockerfile
index 63a353e..f53c733 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.13-slim
+FROM python:3.13-slim@sha256:739e7213785e88c0f702dcdc12c0973afcbd606dbf021a589cab77d6b00b579d
 
 RUN python3 -m venv /opt/venv
 # Activate venv