diff --git a/Dockerfile b/Dockerfile
index fea8ddb1..1bfccd1d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,6 +24,7 @@ COPY --from=deps /app /app
 COPY . .
 RUN pnpm --filter @paperclipai/ui build
 RUN pnpm --filter @paperclipai/server build
+RUN test -f server/dist/index.js || (echo "ERROR: server build output missing" && exit 1)
 
 FROM base AS production
 WORKDIR /app