diff --git a/ui/sign-in/Dockerfile b/ui/sign-in/Dockerfile
index cda694e..d95aa69 100644
--- a/ui/sign-in/Dockerfile
+++ b/ui/sign-in/Dockerfile
@@ -12,10 +12,8 @@ RUN npm run build
 # Stage 2: Logto with sign-in UI + bootstrap
 FROM ghcr.io/logto-io/logto:latest
 
-# Install bootstrap dependencies (curl, jq for API calls; postgresql-client for DB reads)
-RUN apt-get update && apt-get install -y --no-install-recommends \
-    curl jq postgresql-client \
-    && rm -rf /var/lib/apt/lists/*
+# Install bootstrap dependencies (curl, jq for API calls; postgresql16-client for DB reads)
+RUN apk add --no-cache curl jq postgresql16-client
 
 # Custom sign-in UI
 COPY --from=build /ui/dist/ /etc/logto/packages/experience/dist/