diff --git a/Dockerfile b/Dockerfile
index c92f9fb..c380c6a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -15,7 +15,7 @@ COPY . .
 
 RUN CGO_ENABLED=0 go build -o webhook -ldflags '-w -extldflags "-static"' .
 
-FROM alpine:3.18
+FROM alpine:3.23@sha256:51183f2cfa6320055da30872f211093f9ff1d3cf06f39a0bdb212314c5dc7375
 
 RUN apk add --no-cache ca-certificates