diff --git a/sync/Dockerfile b/sync/Dockerfile
index d120c26..a3bd4d0 100644
--- a/sync/Dockerfile
+++ b/sync/Dockerfile
@@ -5,7 +5,7 @@ COPY package*.json ./
 RUN npm ci --include=dev
 COPY tsconfig.json ./
 COPY src ./src
-RUN npm run build && npm prune --production
+RUN ./node_modules/.bin/tsc && npm prune --production
 
 # Stage 2: runtime with Playwright — copy built artifacts, no npm install
 FROM mcr.microsoft.com/playwright:v1.47.0-jammy