diff --git a/Dockerfile b/Dockerfile
index 488de06..54ebe68 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -22,7 +22,7 @@ RUN CGO_ENABLED=0 GOOS=linux go build \
     -o epochcloud-test .
 
 # Runtime stage
-FROM docker.io/library/alpine:3.21
+FROM docker.io/library/alpine:3.23@sha256:865b95f46d98cf867a156fe4a135ad3fe50d2056aa3f25ed31662dff6da4eb62
 
 # Install ca-certificates for HTTPS
 RUN apk --no-cache add ca-certificates