diff --git a/Dockerfile b/Dockerfile
index 524d87b..f788581 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM python:3.12-alpine
+FROM python:3.12-alpine@sha256:7747d47f92cfca63a6e2b50275e23dba8407c30d8ae929a88ddd49a5d3f2d331
 
 RUN apk update && apk --no-cache add gcc musl-dev openjdk17-jdk curl graphviz ttf-dejavu fontconfig