diff --git a/Dockerfile b/Dockerfile
index 82f2bf3..cc8df54 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -16,7 +16,9 @@ WORKDIR /app
 FROM base AS builder
 WORKDIR /build
 COPY package*.json ./
-RUN npm ci
+# Deployment platforms set NODE_ENV=production globally; devDependencies are required to build.
+ENV NODE_ENV=development
+RUN npm ci --include=dev
 COPY . .
 RUN npm run build