diff --git a/docs/syncserver/Dockerfile b/docs/syncserver/Dockerfile
index f7402fcfa..204e24971 100644
--- a/docs/syncserver/Dockerfile
+++ b/docs/syncserver/Dockerfile
@@ -7,6 +7,7 @@ RUN apk update && apk add --no-cache build-base protobuf && rm -rf /var/cache/ap
 RUN cargo install --git https://github.com/ankitects/anki.git \
 --tag ${ANKI_VERSION} \
 --root /anki-server  \
+--locked \
 anki-sync-server
 
 FROM alpine:3.21.0
diff --git a/docs/syncserver/Dockerfile.distroless b/docs/syncserver/Dockerfile.distroless
index 5a7fa6776..db8e81ea1 100644
--- a/docs/syncserver/Dockerfile.distroless
+++ b/docs/syncserver/Dockerfile.distroless
@@ -7,6 +7,7 @@ RUN apt-get update && apt-get install -y build-essential protobuf-compiler && ap
 RUN cargo install --git https://github.com/ankitects/anki.git \
 --tag ${ANKI_VERSION} \
 --root /anki-server  \
+--locked \
 anki-sync-server
 
 FROM gcr.io/distroless/cc-debian12